MCQ IN PHYSICS - 1

Free Solved objective practice Questions on thermodynamics in Physics
Solved Sample Problems Based on Thermodynamics Multiple Choice Practice set on Thermodynamics

1. General gas equation is
(a) PV = RT
(b) PV= mRT
(c) PV = Constant
(d) = constant
ANSWER: (a)

2. An isolated system is one, which
(a) Permits the passage of energy and matter
across the boundaries
(b) Permits the passage of energy only
(c) Does not permit the passage of energy and matter across it
(d) Permits the passage of matter only
ANSWER: (b)

3. In an isolated system, boundary of the system is
crossed by
(a) Heat
(b) Work
(c) Mass
(d) Both (a) and (b) above
ANSWER: (d)

4. The characteristic of a control volume is/are
(a) The volume, shape and position with respect to an observer are fixed
(b) Material flow across the boundary
(c) Both (a) and (b) above
(d) None of the above
ANSWER: (c)

5. Specific heat is the amount of heat required to raise the temperature
(a) By unit degree of a substance
(b) By unit degree of a unit mass
(c) Of a unit mass by 10°
(d) None of the above
ANSWER: (b)

6. Internal energy of a perfect gas depends upon
(a) Temperature only
(b) Temperature and pressure
(c) Temperature, pressure and specific heats
(a) None of the above
ANSWER: (a)

7. With rise of temperature, the specific heat of
water
(a) Increases
(b) Decreases
(c) First decreases to minimum then increases
(d) Remains constant
ANSWER: (c)

8. For a closed system, difference between the heat added to the system and work done by the gas, is
equal to the change in
(a) Enthalpy
(b) Entropy
(c) Internal energy
(d) Temperature
ANSWER: (c)

9. Specific heat of water is
(a) 1
(b) 0.1
(c) 0.97
(d) None of the above
ANSWER: (a)

10. Properties of the system, whose value for the entire system is equal to the sum of their values
for individual parts ofthe system, are known as
(a) Thermodynamic properties
(b) Extensive properties
(c) Intensive properties
(d) None of the above
ANSWER: (b)

1. The extensive property of a thermodynamic system is
(a) Viscosity
(b) Surface tension
(c) Refractive index
(d) Heat capacity
ANSWER: (d)

12. Thermal equilibrium between two or more bodies exists, when they are brought together; there is no change in
(a) Density
(b) Pressure
(c) Temperature
(d) All of the above
ANSWER: (c)

13. When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium
with each other This statement is
(a) Zero the law of thermodynamics
(b) First law of thermodynamics
(c) Second law of thermodynamics
(d) None of the above
ANSWER: (a)

14. First law of thermodynamics deals with conservation of
(a) Mass
(b) Heat
(c) Momentum
(d) Energy
ANSWER: (d)

15. According to first law of thermodynamics
(a) total energy of a system remains constant
(b) total energy of a system during a process
remains constant
(c) enthalpy entropy and total energy remains constant
(d) none of the above
ANSWER: (a)

16. For the measurement of thermodynamic property known as temperature, is based on
(a) Zeroth law of thermodynamics
(b) First law of thermodynamics
(c) Second law of thermodynamics
(b) Third law of thermodynamics
ANSWER: (a)

17. Energy can neither be created nor destroyed but only converted from one form to another. This
statement is
(a) Zeroth law of thermodynamics
(b) First law of thermodynamics
(c) Second law of thermodynamics
(d) None of the above
ANSWER: (b)

18. Kelvin-Plank’s law’ deals with
(a) Conversion of work into heat
(b) Conversion of heat into work
(c) Conservation of work
(d) Conservation of heat
ANSWER: (b)

19. A perpetual motion machine of the first kind is a machine which produces power without
consuming any energy is,
(a) Possible according to first law of thermodynamics
(b) Impossible according to first law of thermodynamics
(c) Impossible according to second law of thermodynamics
(d) Possible according to second law of thermodynamics
ANSWER: (b)

20. Heat flows from cold substance to hot substance with the aid of external work This statement is
given by
(a) Kelvin
(b) Joule
(c) Gay Lussac
(d) Clausius
ANSWER: (d)

21. The fastest moving gas molecules are of
(a) Oxygen
(b) Hydrogen
(c) Chlorine
(d) Nitrogen
ANSWER: (b)

22. In actual gases, the molecular collisions are
(a) Elastic
(b) Plastic
(c) Inplastic
(d) Ineclastic
ANSWER: (d)

23. If a perfect gas, undergoing any change in the variable, which control physical properties, it’s
behaviour is governed by
(a) Boyle’s law
(b) Charles’s law
(c) Gay Lussac law
(d) All of the above
ANSWER: (d)

24. According of Boyle’s law at constant temperature PV= C. In this relation value of C
depends upon
(a) Atmospheric pressure
(b) Quantity Of the gas
(c) Molecular weight of the gas
(d) All of the above
ANSWER: (b)

25. Change of internal energy is proportional to the change of temperature. This is
(a) Boyle’s law
(b) Charles’s law
(c) Joule’s law
(d) Gay Lussac law
ANSWER: (c)

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Solved Objective MCQ test on Fluid mechanics

1. In Red wood viscometer
(a) Absolute value of viscosity is detemiined
(b) Part of the head of fluid is utilized in
Overcoming friction
(c) Fluid discharges through orifice with
negligible velocity
(d) Comparison of viscosity is done.
ANSWER: (d)

2. Centre of buoyancy is
(a) The point of intersection of buoyant force and
centre line of the body
(b) Centre of gravity of the body
(c) Centric of displaced volume fluid
(d) Midpoint between C.G. and metacentric.
ANSWER: (c)

3. In isentropic flow; the temperature
(a) Cannot exceed the reservoir temperature
(b) Cannot drop and again increase downstream
(c) Is independent of Match number
(d) Is a function of Match number only
ANSWER: (a)

4. A stream line is
(a) The line of equal velocity in a flow
(b) The line along which the rate of pressure drop
is uniform
(c) The line along the geometrical centre of the
flow
(d) Fixed in space in steady flow.
ANSWER: (d)

5. The flow of water in a pure of diameter 3000
mm can be measured by
(a) Venturimeter
(b) Rotameter
(c) Pilot tube
(d) Orifice plate.
ANSWER: (c)

6. Apparent shear forces
(a) Can never occur in frictionless fluid
regardless of its motion
(b) Can never occur when the fluid is at rest
(c) Depend upon cohesive forces
(d) All of the above
ANSWER: (d)

7. Weber number is the ratio of
(a) Inertial forces to surface tension
(b) Inertial forces to viscous forces
(c) Elastic forces to pressure forces
(d) Viscous forces to gravity
ANSWER: (a)

8. A small plastic boat loaded with pieces of steel
rods is floating in a bath tub. If the cargo is dumped
into the water allowing the both to float empty, the
water level in the tub will
(a) Rise
(b) Fall
(c) Remains same
(d) Rise and then fall
ANSWER: (b)

9. A flow in which each liquid particle has a
definite path and their paths do not cross each
other, is called
(a) Steady flow
(b) Uniform flow.
(c) Streamline flow
(d) Turbulent flow
ANSWER: (c)

10. Buoyant force is
(a) Resultant of up thrust and gravity forces acting
on the body
(b) Resultant force on the body due to the fluid
surrounding it
(c) Resultant of static weight of body and
dynamic thrust of fluid’
(d) Equal to the volume of liquid displaced by
the body
ANSWER: (d)

11. Cavitations is caused by
(a) High velocity
(b) Low barometric pressure
(c) High pressure
(d) Low pressure
ANSWER: (d)

12. The general energy equation is applicable to
(a) Steady flow
(b) Unsteady flow
(c) Non-uniform flow
(d) Turbulent flow
ANSWER: (a)

13. The friction resistance in Pipe is proportional
To Square of V , according to
(a) Froudeaiumber
(b) Reynolds-Weber
(c) Darcy-Reynolds
(d) Weber-Froude
ANSWER: (a)

14. Pitot tube is used to measure the velocity head of
(a) Still fluid
(b) Laminar flow
(c) Turbulent flow
(d) Flowing fluid
ANSWER: (d)

15. In equilibrium condition, fluids are not able to sustain
(a) Shear force
(b) Resistance to viscosity
(c) Surface tension
(d) Geometric similitude
ANSWER: (c)

16. Flow occurring in a pipeline when a valve is
being opened is
(a) Steady
(b) Unsteady
(c) Laminar
(d) Vortex
ANSWER: (b)

17. Total pressure on 1 m x 1 m gate immersed vertically at a depth of 2 m below the free water
surface will be
(a) 1000 kg
(b) 2000 kg
(c) 4000 kg
(d) 8000 kg
ANSWER: (a)

18. A large Reynold number is indication of
(a) Smooth and streamline flow
(b) Laminar flow
(c) Steady flow
(d) Highly turbulent flow
ANSWER: (d)

19. In steady flow of a fluid, the acceleration of any
fluid particle is
(a) Constant
(b) Variable
(c) Zero
(d) Never zero
ANSWER: (c)

20. Froude number is significant in
(a) Supersonics, as with projectile and jet propulsion
(b) Full immersion or completely enclosed flow, as with pipes, aircrafts wings, nozzles etc.,
(c) Simultaneous motion through two fluids where there is a surface of discontinuity,
gravity forces
(d) All of the above
ANSWER: (c)

21. The flow in venturiflume takes place at
(a) Atmospheric pressure
(b) Vacuum
(c) High pressure
(d) Any pressure
ANSWER: (a)

22. Two dimensional flow occurs when the
(a) Directional and magnitude of the velocity at all points are identical
(b) Velocity of successive fluid particles, at any point, is same at successive periods of time
(c) Magnitude and direction of velocity, do not change from point to point in the fluid
(d) Fluid particles move in a plane or parallel planes and the streamline patterns are
identical in each plane
ANSWER: (d)

23. A piece of wood having weight 5 kg floats in
water with 60% of its volume under the (liquid.
The specific gravity of wood is
(a) 0.83
(b) 0.6
(c) 0.4
(d) None of the above
ANSWER: (b)

24. In order that the water shall never rise more than
100 cm above the crest for a discharge of 5 cubic
metres per second, the length of weir will be
(a) 1 metre
(b) 2.5 metres
(c) 2.49 metres
(d) 2.51 metres
ANSWER: (c)

25. Separation of flow occurs due to reduction of
pressure gradient to
(a) Zero
(b) Negligibly low value
(c) The extent such that vapour formation starts
(d) None of the above
ANSWER: (c)

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Rajasthan Public Service Commission RPSC physics Solved Objective Sample Paper
Physics Solved Practice paper for RPSC prelims Exam
olved Model Paper Physics for RPSC

1. Two parallel wires separated by 25 cm carry currents of i1 = 25 A and i2 = 35 A flowing in opposite directions. The force per unit length acting between them is:
(a) a repulsive force of 7 x 104 N/m
(b) an attractive force of 7 x 10-4N/m
(c) a repulsive force of 35 x 102 N/m
(d) an attractive force of 35 x 102 N/m
Ans. (a)

2. In the case of a series L-C-R circuit, the sharpness of resonance curve is determined by the quality factor Q given by:
(a) XL
XC
(b) L? at resonance frequency
R
(c) L? at any frequency other than resonance frequency
R
(d) XC = XL
Ans. (b)

3. A device used to measure the magnetic field makes use of Hall effect. In a magnetic field of 200 G, it gives a Hall voltage of 16 ?V. If with the same current and orientation, it gives a Hall voltage of 24 ?V in another field, then its magnitude:
(a) 1600G
(b) 480 G
(c) 300 G
(d) 150 G
Ans.(c)

4. Under space charge conditions with the plate voltage Eb = 100 V and the permanence K = 10-4 (in SI unit), the plate current in a diode will be:
(a) 10-6 mA
(b) l02mA
(c) 102 mA
(d) l0mA
Ans. (a)

5. For a BJT, the current amplification factor cc = 0.9. This transistor is connected in CE configuration. When the base current changes by 0.4 mA, the change in collector current will be:
(a) 36 mA
(b) 9 mA
(c) 4 mA
(d) 3.6 mA
Ans. (d)

6. A CE amplifier has voltage gain of 50, an input impedance of 1000 Ohms, and an output impedance of 200 Ohms. The power gain of the amplifier will be:
(a) 24 dB
(b) 41 dB
(c) 250 dB
(d) 12500 dB
Ans. (c)

7. The input signal given to a CE amplifier having a voltage gain of 150 is Vi = 2cos(15t + 10°). The corresponding output signal is:
(a) 300cos(15t +190°)
(b) 300cos(15t + 90°)
(c) 75cos(15t+10°)
(d) 2cos(15t+190°)
Ans. (a)

8. If in the first Bohr orbit of a hydrogen atom the total energy of the electron is 21.76 x 10-19J, then its potential energy will be:
(a) -43.52 x 10-19J
(b) -27.76 x 10-19J
(c) -10.88 x 10-19J
(d) -13.60 x 10-19J
Ans. (a)

9. Match List I with List H and select the correct answer using the codes given below the Lists:
List I List II
(Processes) (Description)
A. Isothermal process 1. No heat exchange
B. Isentropic process 2. Constant temperature
C. Isochoric process 3. Constant pressure
D. Isobaric process 4. Constant volume
5. Constant enthalpy
Codes:
A B C D
(a) 2 1 5 4
(b) 3 2 4 5
(c) 2 1 4 3
(d) 1 5 2 3
Ans. (c)

10. A system absorbs 1.5 x 103J of energy as heat and produces 500 J of work. The change in the internal energy of the system will be:
(a) 50J
(b) 100J
(c) 150J
(d) 1000J
Ans. (d)

11. If a capacitor of 1?F charged to a potential of 300 V is discharged through a resistor kept at room temperature, then the entropy change of the universe in J/K is equal to:
(a) Zero
(b) 0.4 x 10-4
(c) 1.5 x 10-4
(d) 4.0 x 10-4
Ans. (c)

12. The volume of a certain mass of gas at constant pressure is doubled to its value at 0°C. The temperature of the gas will be:
(a) 100° C
(b) 173°C
(c) 273° C
(d) 546° C
Ans. (c)

13. The period of oscillations of a galvanometer mirror due to the Brownian motion is 40 s. The moment of inertia of the galvanometer about its suspensions axis is 8 x 10-12 kg-m2. The root-mean-square of maximum deflection of this mirror at a temperature of 50°C is:
(a) 2.7 x 10-4 rad
(b) 2.1 x 10-4 rad
(c) 1.5 x 10-4 rad
(d) 0.9 x 10-4 rad
Ans. (c)

14. If a black body radiation in a spherical cavity of volume V satisfies the relation PV? = constant during a quasistatic isentropic process, then the numerical value of i should be:
(a) 7/5
(b) 5/3
(c) 4/3
(d) 3/2
Ans. (c)

Direction: The following ten items consists of two statements, one labelled the ‘Assertion A’ and the other labelled the ‘Reason R’. You are to examine these two statements carefully and decide, if the ‘Assertion A’ and the ‘Reason R’ are individually true and if so, whether the
Reason is a correct explanation of the Assertion. Select your answers to these items using the codes given below and mark your answer sheet accordingly.
Codes:
(a) Both A and Rare true and R is the correct explanation of A
(b) Both A and R are true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

15. Assertion (A): The shape of an automobile is so designed that it resembles the streamline pattern of the fluid through which it moves,
Reason (R): Only then the resistance offered by the fluid is maximum
Ans. (c)

16. Assertion (A): When two vibrating tuning forks having frequencies 256 Hz and 512 Hz are held near each other, beats cannot be heard.
Reason (R): The principle of superposition is valid only if the frequencies of the oscillators are nearly equal.
Ans. (a)

17. Assertion (A): Resonance is a special case of forced vibration in which the natural frequency of vibration of the body is the same as the impressed frequency and the amplitude of forced vibration is maximum.
Reason (R): The amplitude of forced vibrations of a body increases with the increase in the frequency of the externally impressed periodic force.
Ans. (c)

18. Assertion (A): A single lens produces a coloured image of an object illuminated by white light.
Reason (R): The refractive index of the material of lens is different for different wavelength of light.
Ans. (a)

19. Assertion (A): At room temperature water does not sublimate from ice to steam.
Reason (R): The critical point of water is much above the room temperature.
Ans. (a)

20. Assertion (A): It is not possible for a system, unaided by an external agency to transfer heat from a body at a lower temperature to another at a higher temperature.
Reason (R): It cannot violate the second law of thermodynamics.
Ans. (a)

21. Assertion (A): In the absence of an externally applied electric field, the dipole moment per unit volume of a polar dielectric material is always zero.
Reason (R): In polar dielectrics each molecule has a permanent dipole moment but these are randomly oriented in the absence of an externally applied electric field.
Ans. (a)

22. Assertion (A): If a heavy nucleus is split into two medium sized ones, each of the new nuclei will have more binding energy per nucleon than the original nucleus.
Reason (R): Joining two light nuclei together to give a single nucleus of medium size means more binding energy per nucleon in the new nucleus.
Ans. (c)

23. Assertion (A): In the process of nuclear fission, the fragments emit two or three neutrons as soon as they are formed and subsequently emit particles.
Reason (R): As the fragments contain an excess of neutrons over .proton, emission of neutrons and ?-1 particles bring their neutron/proton ratio to stable values.
Ans. (a)

24. Assertion (A): The energy gap between the valence band and conduction band is greater in silicon than in germanium.
Reason (R): Thermal energy produces fewer minority carriers in silicon than in germanium.
Ans. (a)

25. A damped simple harmonic oscillator of frequency f1 is constantly driven by an external periodic force of frequency f2. At the steady state, the oscillator frequency will be:
(a) f1
(b) f2
(c) f1 – f2
(d) (f1 + f2)/2
Ans. (b)

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Physics solved previous Objective questions UPSC
physics solved questions for UPSC IAS
UPSC Exam material Physics objective questions and answers
1. Two charged particles A and B have the same linear momentum but A has twice the charge as on B. Both move in circular paths of radii rA and rB about a magnetic field. Which one of the following is the correct value of rA/rB
(a) 2
(b) 0.5
(c) 4
(d) 0.25
Ans. (b)

2. The ground state energy of positronium is:
(a) – 1.2eV
(b) – 3.4 eV
(c) – 6.8eV
(d) – 13.6eV
Ans. (c)

3. The minimum wavelength of continuous X-rays is given by:
(a) eh/Vc
(b) ch/eV
(d) cV/eh
(c) eV/ch
(Where the symbols have their usual significance)
Ans. (b)

4. An X-ray of energy 50 keV strikes an electron initially at rest. The change in wavelength of the X-ray scattered at angle 90°is, approximately:
(Given, h = 6.63 x 10-34 J-s, m = 9.11 x 10-31 kg)
(a) Zero
(b) 2.4x 10-12 m
(c) 4.8 x 10-12 m
(d) 2.7 x 10-11 m
Ans. (b)

5. The relationship between the angular frequency —? and the wave number—k (using de-Brolie’s hypothesis) of a particle associated with it is ? = ck2 , where c is constant. The group velocity for the particle wave is:
(a) 1/2ck
(b) 1 ck
(c) 2 ck
(d) 4 ck
Ans. (c)

6. A radioactive sample containing No nuclei emits N particles per second on decaying. The half-life of the sample, in seconds is:
(a) 0.693 (N/No)
(b) (N/No)
(c) 0.693 (No/N)
(d) (No/N)
Ans. (c)

7. For which of the following cases is the de-Broglie wavelength same?
1. Particle of mass m, kinetic energy K
2. Particle of mass 2m, kinetic energy 2K
3. Particle of mass 2m, kinetic energy
Select the correct answer using the codes given below:
(a) 2 and 3
(b) 1 and 3
(c) 1 and 2
(d) 1, 2 and 3
Ans. (d)

8. If E0 is the zero-point energy of a harmonic oscillator of frequency v and h is Planck’s constant then its energy in the n = 2 state will be:
(a) (E0 + hv)
(b) 2E0
(c) 4E0
(d) (E0 + 2hv)
Ans. (d)

9. A threshold wavelength of a metal is 7000 A. The work function is: (Given, velocity of light c = 3 x 108 m/s and Planck’s constant 6.624 x 10-34 J-s)
(a) 1.775 eV
(b) 17.75 eV
(c) 177.5 eV
(d) 0.8875 eV
Ans. (a)

Directions: The following items consist of two statements, one labeled the ‘Assertion (A)’ and the other labeled the ‘Reason (R)’. You are to examine these two statements carefully and decide, if the ‘Assertion (A)’ and the ‘Reason (R)’ are individually true and if so, whether the ‘Reason (R)’ is a correct explanation of the ‘Assertion (A)’. Select your answers to these items using the Codes given below and mark your answer sheet accordingly:
Codes:
(a) Both A and Rare true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

10. Assertion (A): While traveling through air, sound waves, from two different sources, pass through each other without being destroyed.
Reason (R): The frequency of simple harmonic waves is independent of their amplitude.
Ans. (b)

11. Assertion (A): Two ships sail parallel and close to each other during a naval exercise. To achieve this they are to be steered slightly outwards.
Reason (R): Flow of liquid to drag in the channel produces excess pressure above the normal on the outer sides of the ships, which pushes them inwards.
Ans. (a)

12. Assertion (A): A skater brings his hands closer to his body to spin faster.
Reason (R): Only then his moment of inertia will decrease and angular velocity will increase.
Ans. (a)

13. Assertion (A): The pressure of air inside a small soap bubble is greater than the pressure of air inside a larger bubble.
Reason (R): The pressure of air is inversely proportional to the surface area of the bubble.
Ans. (a)

14. Assertion (A): The spherical aberration in a plano-convex lens is reduced, if its spherical surface faces the incident parallel light.
Reason (R): In a lens spherical aberration is minimized, if the total deviation produced by a lens is equally shared by two surfaces.
Ans. (a)

15. Assertion (A): The most common solution to the problem of eliminating chromatic aberration is achieved with a chromatic doublet.
Reason (R): When lenses are combined to form a doublet, spherical aberration may be minimized.
Ans. (6)

16. Assertion (A): The central fringe in the reflected light of Newton’s rings between a piano-convex lens and a plane glass plate is dark in the absence of any dust particles.
Reason (R): When a ray of light undergoes reflection at the surface of a denser medium it suffers a phase change of it.
Ans. (a)

17. Assertion (A): A 1 mW He-Ne laser is hundred times brighter than the intensity of sunlight on earth.
Reason (R): Laser beam is highly directional.
Ans. (a)

18. Assertion (A): At 0 K, the molecules of a gas possess no energy.
Reason (R): At absolute zero temperature the molecule of a gas possess some energy called zero point energy
Ans. (b)

19. Assertion (A): At a given temperature radiations emitted by pin hole cavities in different materials are different.
Reason (R): Pinhole cavities in all materials behave like perfect black body.
Ans. (d)

20. Assertion (A): If a body is in thermal equilibrium with the surroundings, then it will absorb and emit radiant energy at the same rate.
Reason (R): Stefan-Boltzmann law is true for both emission and absorption of radiant energy
Ans (c)

21. Assertion (A): The study of Hall Effect can give the sign of charge carriers in a conductor.
Reason (R): The sign of charge carriers is determined by the sign of the Hall potential which is developed in-the lateral direction of the current.
Ans. (a)

22. Assertion (A): In Stern-Gerlach experiment the single beam of silver atoms after passing through non-homogeneous magnetic field was split into two distinct parts.
Reason (R): Space quantization permits two opposite spin directions, resulting in the deflection of the beam in two opposite directions.
Ans. (a)

23. Assertion (A): An electron cannot be observed without changing its momentum by an indeterminate amount.
Reason (R): Momentum of an electron is h/? where is its wavelength.
Ans. (b)

24. Assertion (A): Uniform magnetic field B has a non-zero divergence at the pole of a bar magnet.
Reason (R): Magnetic field cannot transfer energy to charged particles.
Ans. (d)

25. Assertion (A): Electrons find greater attractive forces by collector once they reach the base from an emitter in n-p-n transistor operation.
Reason (R): The reverse bias voltage on the collector is much higher than the forward bias on the emitter.
Ans. (a)

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Objective physics Sample paper

solved physics Sample paper for PMT PET CBSE Physics
1. A machine gun fires n bullets per second and the mass of each bullet is m. If the speed of bullets is v, then the force exerted on the machine gun is
(a) mng
(b) mnv
(c) mnvg
(d) mnv/ 8
Ans. (b)

2. A Diwali rocket is ejecting 0.05 kg of gases per second at a velocity of 400 ms-1.
The accelerating force on the rocket is
(a) 0 dyne
(b) 20 newton
(c) 20 kg wt
(d) sufficient data not given
Ans. (b)

3. A stretching force of 100 N is applied at one end of a spring balance and an
equal stretching force is applied at the other end at the same time. The reading
on the balance will be
(a) 200 N
(b) 100 N
(c) 400 N
(d) zero
Ans. (b)

4. Aluminium has a density of 2.7 g/cc. The mass of 15 cc of aluminium is
(a) 45 g
(b) 40.5 g
(c) 80 g
(d) 100 g
Ans. (b)

5. 60 cc of a liquid of relative density 1.4 are mixed with 40 cc of another liquid of
relative density 0.8. The density of the mixture is
(a) 1.16 g/cc
(b) 2.26 g/cc
(c) 11.6 g/cc
(d) 116 g/cc
Ans. (a)

6. The height of mercury which exerts the same pressure as 20 cm of water column, is
(a) 1.47cm
(b) 14.8 cm
(c) 148 cm
(d) none of these
Ans. (a)

7. The hot air balloon rises because it is
(a) denser
(b) less dense
(c) equally dense
(d) the given statement is wrong
Ans. (b)

8. A boat full of iron nails is floating on water in a lake. When the iron nails are
removed, the water level
(a) rises
(b) falls
(c) remains the same
(d) nothing can be said
Ans. (b)

9. A solid weighs 32 g f in air and 28.8 g f in water. The R.D. of the solid is
(a) 8.9
(b) 10
(c) 29.12
(d) 20
Ans. (b)

10. If the density of a metal is 8.2 g/cc, its relative density is
(a) 8.2
(b) 1/ 8.2
(c) 0.82
(d) none of these
Ans. (b)

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Physics Solved Objective Questions For RRB Exams
Physics Model questions Fully Solved
RRB ASM General Knowledge : Physics Solved Paper
1. A bullet of mass A and velocity B fired into a block of wood of mass C. If loss of any
mass and friction be neglected, the velocity of the system must be
(a) AB/A+C
(b) A+C/B+C
(c) AC/B+C
(d) A+B/AC
Ans. (a)

2. A rocket works on the
(a) first law of motion
(b) second law of motion
(c) third law of motion
(d) law of conservation of energy
Ans. (c)

3. 1 dyne is equal to
(a) 980 g wt
(b) 1/100 g wt
(c) 980 kg wt
(d) none of these
Ans. (b)

4. Two skaters A and B of mass 50 kg and 70 kg respectively stand facing each other
6 metres apart. They then pull on a light rope stretched between them. How far has
each moved when they meet?
(a) Both have moved 3 metres.
(b) A moves 2.5 metres and B moves 3.5 metres.
(c) A moves 3.5 metres and B moves 2.5 metres.
(d) A moves 2 metres and B moves 4 metres.
Ans. (c)

5. A body of mass M collides against a wall with velocity V and rebounds with the same speed. Its change of momentum is
(a) zero
(b) MV
(c) 2MV
(d) –MV
Ans. (c)

6. A bullet in motion hits and gets embedded in a solid resting on a frictionless table.
What is conserved?
(a) Momentum and kinetic energy
(b) Momentum alone
(c) Kinetic energy alone
(d) Neither momentum nor kinetic energy
Ans. (b)

7. A man sitting in a train in motion is facing the engine. He tosses a coin up,
the coin falls behind him. The train is moving
(a) forward with uniform speed
(b) backward with uniform speed
(c) forward with acceleration
(d) forward with deceleration
Ans. (b)

8. If the mass of a body is 12.1 g and the density is 2.2 g/cc, its volume is
(a) 1.5 cm3
(b) 8 cc
(c) 11 cc
(d) 55 cc
Ans. (a)

9. Brine has a density of 1.2 g/ccc. 40 cc of it are mixed with 30 cc of water.
The density of solution is
(a) 2.11 g/ccc
(b) 1.11 g/ccc
(e) 12.2 g/ccc
(d) 20.4 g/ccc
Ans. (b)

10. If a force of 10 N acts on surfaces of areas in the ratio 1: 2. then the ratio of
thrusts is
(a) 1:2
(b) 2:1
(c) 3:1
(d) 1.1
Ans. (d)

11. The buoyant force depends on the
(a) depth of a liquid
(b) density of a liquid
(c) colour of a liquid
(d) none of these
Ans. (b)

12. A force of 50 N is applied on a nail of area 0.00 1 sq. cm. Then the thrust is
(a) 50 N
(b) 100 N
(c) 0.05 N
(d) 10 N
Ans. (a)

13. A piece of wood floats in water. What happens to it in alcohol?
(a) Floats higher
(b) Stays as before
(c) Sinks
(d) Sinks and rises
Ans. (c)

14. An ice cube is floating in a glass of water. What happens to the water level when
the ice melts?
(a) Rises
(b) Falls
(c) remains same
(d) First rises and then falls
Ans. (c)

15. The SI unit of pressure is
(a) atmosphere
(b) dyne/cm2
(c) pascal
(d) mm of Hg
Ans. (c)

16. A body of mass 50 kg has a volume 0.049 m3.The buoyant force on it is
(a) 50 kg f
(b) 50N
(e) 49N
(d) 49kg f
Ans. (d)

17. If two masses A and B have their masses in the ratio 1: 4 and their volumes are equal,
then the densities have the ratio
(a) 1:4
(b) 4:1
(c) 2:1
(d) 3:1
Ans. (a)

18. If the density of a block is 981 kg/m3, it shall
(a) sink
(b) float
(c) float completely immersed in water
(d) float completely out of water
Ans. (b)

19. As the density of a series of liquids increases, the upthrust on the iron rod submerged
(a) increases
(b) decreases
(c) remains constant
(d) nothing can be said
Ans. (a)

20. The SI unit of thrust is
(a) N
(b) dyne
(c) kg wt
(d) N m-2
Ans. (a)

21. The total force exerted by the body perpendicular to the surface is called
(a) pressure
(b) thrust
(c) impulse
(d) none of these
Ans. (a)

22. At sea level, atmospheric pressure is
(a) 76 cm of Hg column
(b) 76 cm of Hg column
(c) 0.76 cm of Hg column
(d) 76 cm of water column
Ans. (a)

23. Atmospheric pressure is measured by a
(a) doctor’s thermometer
(b) peedometer
(c) mercury barometer
(d) none of these
Ans. (c)

24. The weather forecasting department uses………as the unit of pressure,
(a) bar
(b) N m-2
(c) Pa
(d) mm of Hg
Ans. (a)

25. Which of the following physical quantity has no unit?
(a) Relative density
(b) Density
(c) Pressure
(d) Thrust
Ans. (a)

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Physics For UPSC IAS
Physics Civil Service Exam practice test IAS Preliminary
UPSC Civil Services Prelims Examination Practice – Physics

1. The magnetic field through a coil changes at uniform rate from 0.1 T to 0.4 T during 2 x 102s. If the area of cross-section of the coil is 4 x 10-2 m2 and the number of turns is 200, then the emf induced in the coil is:
(a) 50 V
(b) 120 V
(c) 180 V
(d) 220 V
Ans. (b)

2. A coil of N turns, made of copper wire of length 4 m is placed in a magnetic field that changes with time. The value of N, for which induced emf will be maximum, is:
(a) 1
(b) 2
(c) 3
(d) 4
Ans. (d)

3. A current of I A is passed through a semiconductor material of thickness 1 mm. It is placed in a transverse magnetic field of 1 T. If the earner density is 1025/m2, then the Hall potential is:
(a) 63 mV
(b) 6.3 mV
(c) 0.63 mV
(d) 0.063 mV
Ans. (c)

4. If a plane electromagnetic wave propagating in space has an electric field of amplitude 9 x 103 V/m, then the amplitude of the magnetic field is:
(a) 2.7 x 1012T
(b) 9.0 x 10-3 T
(c) 3.0 x 10-4T
(d) 3.0 x 10-5T
Ans. (d)

5. A cyclotron of radius 64 cm accelerates deuterons (m = 3.3 x 10-27 kg). If the cyclotron frequency is 5 MHz, then the maximum speed with which the deuterons
Emerge, is
(a) 3 x 107m/s
(b) 2 x 107m/s
(c) 1.5 x 107m/s
(d) 2 x 106m/s
Ans. (b)

6. In a typical electron synchrotron, the magnetic field:
(a) Is varied with time while the radio frequency is held constant
(b) Is held constant while the radio frequency is varied with time
(c) As well as the radio frequency are varied with time
(d) As well as the radio frequency are held constant
Ans. (c)

7. Consider the following statements:
Stern and Gerlach experiment gives a direct and convincing confirmation of:
1. Space quantization.
2. Wave nature of electron.
3. Spin of electron.
4. quantized atomic magnetic moment.
Which of the above statements are correct?
(a) 3 and 4
(b) 1,2and4
(c) 1,3and4
(d) 1 and 2
Ans. (c)

8. Lionization potential for a hydrogen atom is 13.6 eV. The ionization potential for a positronium atom where an electron revolves round a positron, is:
(b) 6.8 eV
(a) 13.6 eV’
(c) 3.4 eV
(d) 1.7 eV
Ans. (b)

9. The glancing angle in a X-rays diffraction experiment is 30° and the wavelength of the X-rays used is 20 nm. The inter planar spacing of the crystal diffracting these X-rays will be
(b) 20 nm
(a) 40 nm
(c) 15 nm
(d) l0 nm
Ans. (b)

10. If a proton and an electron have same de-Broglie wavelength, then:
(a) Both have same kinetic energies
(b) Proton has more kinetic energy than electron
(c) Electron has more kinetic energy than proton
(d) Both have same velocity
Ans. (c)

11. Six a-decays and a number of 13-decays occur before 90Th232 achieves stability; the final product in the chain being 82Pb208. The number of ?-disintegrations taking place is:
(a) 2
(b) 4
(c) 6
(d) 8
Ans. (b)

12. Two. Substances X and Y are made radioactive and contain equal number of atoms. X has half-life of 1 h and Y has half-life of 2 h. After a lapse of 2 h, the ratio of the rate of disintegration of X to that of Y will be:
(a) 1: 4
(b) 2: 1
(c) 1: 1
(d) 1: 2
Ans. (b)

13. An unstable particle of rest energy 1000 MeV ecays into aµ-meson and a neutrino, with a mean life time of 10-8 s, when at rest. The mean decay distance, in meters, when the particle has a momentum of 1000 MeV/c is:
(a) 3
(b) 6
(c) 9
(d) 12
Ans. (a)

14. Consider the following statements about a neutron:
1. Neutron is a fermion.
2. A neutron is heavier than a proton.
3. A free neutron is an unstable particle.
Which of the above statements are correct?
(a) 1, 2 and 3
(b) 1 and 2
(c) 2 and 3
(d) 1 and 3
Ans. (a)

15. The annihilation of a slow positron and an electron cannot result into a photon, but must produce at least two photons traveling in opposite directions. This implies conservation of:
(b) Energy
(a) Baryons
(c) Leptons
(d) Momentum
Ans. (d)

16. The energy of a particle in a potential box and that of the hydrogen atom varies with the quantum number n, respectively, as:
(a) n2 and 1/n2
(b) 1/n2 and n2
(c) n2
(d) 2/n2 and 1/n2
Ans. (a)

17. An excited state of hydrogen atom has a life tithe of 2.5 x 10-14 s. The minimum error in the measurement of the energy of the excited state will be:
(a) 1.656 x 10-40 erg
(b) 1.656 x 10-40 J
(c) 2.65 x 10-13erg
(d) 2.65 x 10-13J
Ans. (c)

18. If input impedance of an FET is R1, and that of a BJT is R2, then:
(a) R1>R2
(b) R1 (c) R1 = R2
(d) None of these
Ans. (a)

19. The correct sequence of the band-gaps of germanium (Eg1) silicon (Eg2) and gallium arsenide (Eg3) will be:
(a) Eg1 > Eg2 > Eg3
(b) Eg1 < Eg2 (c) Eg2 < Eg1 < Eg3
(d) Eg2 > Eg1 > Eg3
Ans. (c)

20. The Fermi level of an intrinsic semiconductor is pinned at the centre of the band-gap. The probability of occupation of the highest electron state in valence band at room temperature will be:
(a) Zero
(b) Between zero and half
(c) Half
(d) One
Ans. (c)

21. If a semiconductor has an intrinsic carrier concentration of 1.41 x 1016/m3 when doped with 1021/m3 phosphorus atoms, then the concentration of holes/m3 at room temperature will be:
(a) 2 x 1021
(b) 2 x 1011
(c) 1.41 x 10
(d) 1.41 x 1016
Ans. (a)

22. A n-p-n transistor circuit has ? = 0.985. If IC = 2 mA, then the value of Ib is:
(a) 0.03 mA
(b) 0.003 mA
(c) 0.66 mA
(d) 0.015 mA
Ans. (a)

23. The DC load line of an amplifier circuit:
(a) Has a positive slope
(b) Has a curvature
(c) Does not contain the Q-point
(d) Has a negative slope
Ans. (d)

24. If a transistor amplifier has a gain of 20 dB, then the ratio of output to input power is:
(a) 100
(b) 10
(c) 20
(d) 200
Ans. (a)

25. for a square-wave response (with respect to its maximum response), the rise-time of a transistor is defined as the time duration in which its response varies from:
(a) 10% to 50%
(b) 0% to 50%
(c) 10% to 90%
(d) 25% to 75%
Ans. (c)

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Physics MCQ test Free online

PHYSICS Practice objective test

1. If the energy, B = G r where G is the universal gravitational constant, h is the Planck’s constant and c is the velocity of light, then the values of p, q and r are, respectively:
(a) – ½, ½ and 5/2
(b) ½, – ½ and 5/2
(c) – ½, ½ and 3/2
(d) ½, – ½ and 3/2
Ans. (a)
2. Two bodies A and B start from rest and from the same point with a uniform acceleration of 2 m/s2 If B starts one second later, then the two bodies are separated, at the end of the next second, by:
(a) 1 m
(b) 2 m
(c) 3 m
(d) 4 m
Ans. (c)

3. A 25 kg crate, starting from rest at the top, slides down a plane that makes an angle of 30° with the horizontal. When it reaches the bottom of the l0m long slide, its velocity is 8 m/s. The work done by the force of friction is closest to a value of
(a) 17.0 x l02J
(c) 6.5 x 102J
(b) 8.0 x l02J
(d) 4.5 x 102J
Ans. (d)

4. A particle of mass 10 kg is moving in a straight line. If its displacement, x With time t is given by, x = (t3 – 2t – 16)m, then the force acting on it at the end of 4 s is:
(a) 24N
(c) 300N
(b) 240N
(d) 1200N
Ans. (b)

5. A golf ball of mass 005 kg placed on a tee, is struck by a golf club. The speed of the golf ball as it leaves the tee is 100 m/s. the time of contact between them is 0.02 s. If the force decreases to zero linearly with time, then the force at the beginning of the contact is
(a) 500 N
(b) 250 N
(c) 200 N
(d) 100 N
Ans. (a)
6. The moment of a inertia of a dumb-bell, consisting of point masses m1 = 2.0kg and m2 = 1.0kg, fixed to the ends of a – rigid massless rod of length L 0.6 m, about an axis passing through the centre of mass and perpendicular to its length, is:
(a) 0.72 kg-m2
(b) 0.36 kg-m2
(c) 0.27 kg-m2
(d) 0.24 kg-m2
Ans. (d)

7. A merry-go-round starting from rest accelerates for 5 s with an angular acceleration of 0.4 rad/s 2 It then rotates at constant angular velocity for 30s before slowing down at the same rate. The distance covered by a thud, sitting on a toy-horse 3 m from the centre, is:
(a) 35 m
(b) 55m
(c) 105 m
(d) 210m
Ans. (d)

8. Two springs A and B with spring constants, kA =2kB are stretched by applying forces of equal magnitudes at their ends. If the energy stored mA is E, then the energy stored in B is.:
(a) E/4
(b) E/2
(c) E
(d) 2E
Ans. (d)

9. In a circus, a person with a mass of 70 kg stands without any floor-support against the wall of a cylindrical rotor. If the coefficient of friction between the rotor-wall surface and the man’s feet is 0.4 and radius of rotor is 2.0 m, then the minimum angular speed of rotor such that the person does not fall, should be:
(a) 7.0 rad/s
(b) 1.75 rad/s
(c) 3.5 rad/s
(d) 5.25 rad/s
Ans. (c)
10. A comet moves in an elliptical orbit with an eccentricity of e = 0.20 around a star. The distance between the perihelion and the aphelion is 1.0 x 108km. If the speed of the comet at perihelion is 81 km/s. then the speed of the comet at the aphelion, is:
(a) 182 km/s
(b) 36 km/s
(c) 121.5 km/s
(d) 54 km/S
Ans. (a)

11. A chair is suspended from a spring with spring constant of 600 N/m. The periodic time for oscillation of system is 1 s. When a man sits in this chair, the periodic time becomes 2.5 s. The weight of the man is closest to a value of:
(a) 650 N
(b) 800 N
(c) 950 N
(d) 1100 N
Ans. (b)

12. When a spring is stretched by a distance x, it exerts a force, given by F = (-5x -16×2) N. The work done, when the spring is stretched from 0.1 m to 0.2 m, is
(a) 8.1 x 10-2J
(b) 12.2 x 10-2J
(c) 8.1 x 10-1J
(d) 12.2 x 10-1J
Ans. (a)

13. If the momentum of an electron moving with a velocity 0.9 c is increased by 1%, then the increase in its energy is:
(a) 1%
(b) 0.9%
(c) 0.81%
(d) 0.5%
Ans. (a)

14. An inertial frame of reference B is moving along the X-axis with a velocity 9 x 106 m/s with respect to another inertial frame A. A rod is located in the frame A with its two ends at the coordinate points (5, -5, 0) m and (5, 7, 5) m. The length of the rod as observed from the frame B is
(a) 13.5m
(b) 13.0m
(c) 12.75 m
(d) 12.5
Ans. (b)

15. A rain drop of radius 1.5 mm, experiences a drag force, F = (2 x 10-5v) N, while falling through air from a height of. 2 km, with a velocity V. The terminal velocity of the rain drop will be nearly:
(a) 200 m/s
(b) 80 m/s
(c) 7 m/s
(d) 3 m/s
Ans. (c)

16. Two traveling waves
y1 = 0.65 sin (0.4x – 800t) m
And y2 = -0.65 sin (0.4x + 800t) m
Are superposed in a medium. For the resultant wave at the point x = 2.5? m, the maximum displacement is:
(a) Zero
(c) 0.65 m
(b) 1.30m
(d) 0.91 m
Ans. (b)

17. The maximum amplitude in the case of a forced oscillator occurs at the
(a) Natural frequency of the oscillator
(b) Frequency of the force
(c) Frequency greater than the natural frequency of the oscillator
(d) Frequency less than the natural frequency of the oscillator
Ans. (d)

18. A sound source S of frequency 1125 Hz is moving towards a stationary observer O with a speed of 29 m/s. Then O perceives it as a frequency of v1. If s is stationary while O is moving towards S, with the same speed, the frequency perceived by O, is v2. If the velocity of sound is 343 m/s, then v1 and v2 are, respectively:
(a) 1229; 1220
(b) 1220; 1229
(c) 1224; 1224
(d) 1224; 1232
Ans. (a)

19. The temperature in Kelvin, at which the average speed of H2 molecules will be same as that of N2 molecules at 35° C, will be
(a) 22
(b) 42
(c) 295
(d) 495
Ans. (a)

20. Consider the following statements regarding the characteristics of entropy:
1. Entropy is a measure of disorder.
2. Entropy changes during a reversible adiabatic process.
3. Entropy of a system decreases in all irreversible processes.
4. Change in entropy for complete reversible thermodynamic cycle is zero.
Which of the above statements are correct?
(a) 1 and 2
(b) 2 and 3
(c) 3 and 4
(d) 1 and 4
Ans. (d)

21. A Carnot engine whose low-temperature reservoir is at 27°C has efficiency 37.5%. The high-temperature reservoir is at
(a) 480°C
(b) 327°C
(c) 307°C
(d) 207°C
Ans. (d)

22. Colloidal particles of mass M are suspended in a gas at 300 K and 1 atm. The most probable energy of these particles is equal to the kinetic energy of a gas molecule moving with the most probable velocity Vp, at the temperature:
(a) 450 K
(b) 380 K
(c) 300 K
(d) 150 K
Ans. (c)

23. In the van der Waals’ equation, the terms (a/V2) and (b) are introduced to account for the:
(a) Inter-molecular attraction and the total volume occupied by the gas
(b) Molecular size and the size of the containing vessel
(c) Inter-molecular attraction and the volume of the molecules
(d) Inter-molecular attraction and the force exerted by the molecules on the walls of the container
Ans. (d)

24. In the spectrum of black body radiation, the distribution of energy switches from adherence to Planck’s law, to Wien’s law (in short Wavelength region) because of the fact that both these laws:
(a) Assume continuous variation of energy
(b) assume discontinuous Variation of energy
(c) Use the same expressions for different modes of vibration
(d) Lead to very small values for the probability factor
Ans. (b)

25. The phenomenon of viscosity in gases is associated with momentum transport from ‘high velocity’ region to ‘low velocity’ region. The mean square velocity of those molecules which participate in the transfer of momentum across a hypothetical layer of the gas is given by:
(a) 2kT/m
(b) 8kT/m
(d) 3kT/m
(c) 4kT/m
Ans. (b)

...........................................................---------------------------------------------..............................

Solved UPSC Physics Questions
physics solved questions for UPSC IAS
Sample Test papers Model Questions physics for UPSC
1. Two organ pipes closed at one end, when blown simultaneously produce 4 beat /s. If the length of the shorter pipe is 0.75 m, the length of the other will be (velocity of sound = 330 m/s)
(a) 1m
(b) 0.87m
(c) 0.82m
(d) 0.78m
Ans. (d)

2. Two glass slabs of thickness 6 cm and 7 cm with refractive indices 1.5 and 1.75 respectively, are placed one above the other on an ink drop. The apparent depth of the ink drop is
(a) 8 cm
(b) 5 cm
(c) 2 cm
(d) 6.5 cm
Ans. (a)

3. A prism of glass (n = 1.5) has the prism angle as 60°. If angles of incidence and emergence at first and second refracting faces are i1 and i2, then for minimum deviation
(a) i1 = i2
(c) i1 > i2
(b) i1 = 0
(d) i1 < i2
Ans. (a)

4. Indicate the color of light, among the following, which travels through glass with the minimum speed:
(a) Red
(c) Yellow
(b) Green
(d) Violet
Ans. (d)

5. Objectives of a pair of binoculars have apertures 60 mm and focal length 250 mm. The ocular aperture is 250mm and focal length 22 mm. The angular magnification is, approximately:
(a) 11.4
(b) 114
(c) 1140
(d) 11400
Ans. (a)

6. Two lenses separated by a distance- t and having the focal lengths f1 and f2 respectively, are made of the same material. Then the chromatic aberration will be minimum, if t is equal to:
(a) 2 (f1 + f2)
(b) 2 (f1 – f2)
(c) (f1 – f2)/2
(d) (f1 + f2)/2
Ans. (d)

7. Spherical aberration is minimized by
1. Use of stops.
2. Use of piano-convex lens.
3. Using two suitable lenses in contact.
4. Using two piano-convex lenses separated by a distance.
Which of the above statements are correct?
(a) 3 and 4
(b) 1, 2 and 4
(c) 1, 2 and 3
(d) 1, 2, 3 and 4
Ans. (d)

8. An object of 12 mm height is placed at a distance of 80 cm to the left of a lens of power + 2.5 D made of glass of refractive index 1.5. The size of the image is:
(a) 3mm
(b) 6mm
(c) 12mm
(d) l8mm
Ans. (c)

9. A telescope has a convex lens of focal length 100 cm as objective and a concave lens of focal length 1 cm as eye-piece. When focused to infinity, the distance between the two lenses:
(a) Is l0l cm
(b) Is l00 cm
(c) Is 99 cm
(d) Depends on the apertures
Ans. (c)

10. A microscope has three objectives, of focal lengths
16 mm, 4 mm and 1.6 mm; an optical tube length of
16 cm and eyepieces marked 5x and l0x. The highest magnification possible is:
(a) + l000x
(b) +l0000x
(c) + 5000x
(d) + 50000 x
Ans. (c)

11. Consider the following statements when a steel ball hits a clay chunk in air and gets embedded in it, then
1. Both the momentum and the energy conserved.
2. Only momentum is conserved.
3. Energy is used to deform the clay chunk.
4. Momentum is not conserved.
Which of the above statement(s) is/are correct?
(a) l only
(b) 2 and 3
(c) 3 and 4
(d) l and 3
Ans. (b)

12. A wooden block having a mass of 1 kg is placed on a table. The block just starts to move, when a force of 10 N is applied at 45° to the vertical to push the block. The coefficient of friction between the table and the block, (taking g =10 m/s2) is approximately:
(a) 0.2
(c) 0.6
(b) 0.4
(d) 0.8
Ans. (d)

13. A tunnel is dug through the earth from one side to the other along a diameter. A metallic ball having diameter smaller than the diameter of the tunnel is dropped from one side. The correct motion of the ball is it:
(a) Executes SHM about the centre of earth
(b) Stops at the centre of the earth
(c) Freely passes out through the other end of the tunnel
(d) Does not pass through the tunnel
Ans. (a)

14. For a particle undergoing a circular motion with uniform velocity the velocity is:
(a) Radial, acceleration is radial
(b) Transverse, acceleration is radial
(c) Transverse, acceleration is transverse
(d) Radial, acceleration is transverse
Ans. (b)

15. Consider the earth to be a perfect sphere and having uniform mass distribution. R is the radius of the earth and x is the distance from the centre of the earth. The gravitational intensity is largest (absolute value) when x is:
(a) Zero
(c) Equal to R
(b) In between zero and R
(d) Greater than R
Ans. (c)

16. The velocity of a particle at which its mass is double its rest mass (where c is velocity of light), is:
(a) 0.75 c
(b) 0.80 c
(c) 0.85 c
(d) 0.95 c
Ans. (c)

17. What is the work done on a particle of rest mass m0 in order to increase its speed from 0.6 c to 0.8 C?
(a) 5m0c2/12
(b) 5m0c2/6
(c) 5m0c2/24
(d) m0c2/7
Ans. (c)

18. A streamline represents a fixed path followed by an orderly procession of fluid particles. If A, B and Care any three points on a streamline and v1, v2 and v3 are the velocities of the fluid particles at those points, then which one of the following statements is not correct?
(a) v1, v2 and v3 are equal to each other at all points
(b) Any particle at anytime has a velocity v1 at v2 at B and v3 at C
(c) All particles passing through A also pass through B and C
(d) v1, v2 and v3 are tangential to the direction of flow at A, B and C respectively
Ans. (a)

19. Two particles execute simple harmonic motions of the same amplitude and frequency along the same straight line. They pass one another traveling in opposite directions, whenever their displacement is half their amplitude. The phase difference between the two is:
(a) 2?/3
(b) ?
(c) ?/6
(d) ?/3
Ans. (a)

20. Two simple harmonic waves, when fed simultaneously to the X and Y plates of a CRO trace a circle on the screen. Then both the waves have
1. The same frequency
2. The same amplitude
3. A constant phase difference of
Which of the above statements are correct?
(a) 1 and 2
(b) 2 and 3
(c) 1 and 3
(d) 1, 2 and 3
Ans. (d)

......................................................................-------------------------------------................................

Physics Solved Quiz for UPSC
UPSC Question Paper, UPSC Sample Paper Free Online
Physics Quiz Questions for IAS, UPSC, NDA and other competitive exams
1. A heated body emits radiation which has maximum intensity at frequency Vm. If the temperature of the body is doubled
(1) The maximum intensity radiation will be at frequency 2Vm
(2) The maximum intensity radiation will be at frequency (l/2) Vm
(3) The total emitted energy will increase by a factor of 2
(4) The total emitted energy will increase by a factor of 16
Ans. (2)

Section-B
Direction: In the following questions more than one of the answers given may be correct. Select the correct answers and mark it according to the code.
Code:
(a) 1, 2 and 3 are correct
(b) 1. and 2 are correct
(c) 2 and 4 are correct
(d) 1 and 3 are correct

2. Let V and E denote the gravitational potential and gravitational field at a point. It is possible to have
(1) V=0 and E=0
(2) V?0 and E=0
(3) V?0 and E?0
(4) V=0 and E?0
Ans. (a)

3. A steel cube weighs 1 kg in air and 0.88 kg in water. The density of the steel is
7.71 x103 kg/m3 and of water is103 kg/m3. The cube
(1) Must be solid
(2) Consists of impure steel
(3) Must be hollow
(4) Consists of pure steel
Ans. (b)

4. Which of the following are not correct about centre of mass?
(1) It depends on frame of reference
(2) Internal forces may affect the motion of centre of mass
(3) Centre of mass and centre of gravity are synonymous
(4) In centre of mass frame momentum of a system is always zero
Ans. (1)

5. If a particle travels a linear distance at speed v1 and comes back along the same track at speed v2.
(1) Its average speed is arithmetic mean (v1 +v2)/2
(2) Its average speed is harmonic mean 2v1v2/ (v1+v2)
(3) Its average speed is geometric mean?v1v2
(4) Its velocity is zero
Ans. (3)

6. Apparent weight of a body in an elevator is more than rest weight. If elevator is
(1) Going up and slowing down
(2) Going up and speeding up
(3) Going down and speeding up
(4) Going down and slowing down
Ans. (3)

7. Let V and E denote the gravitational potential and gravitational field at a point. It is possible to have
(1) V=0 and E=0
(2) V?0 and E=0
(3)V?0 and E?0
(4)V=0 and E?0
Ans. (1)

8. For an isolated system in the absence of any dissipative effect
(1) ICE is conserved
(2) Total energy is conserved
(3) PE is conserved
(4) Mechanical energy is conserved
Ans. (3)

9. Which of the following statements are correct?
(1) Young’s modulus, bulk modulus and shear modulus have the units of pressure
(2) Young’s modulus describes the length elasticity of a material
(3) The value of Young’s modulus depends on the dimensions of the body
(4) Modulus of elasticity is the smallest value of stress required to produce a permanent distortion in a body
Ans. (4)

10. A steel cube weighs 1 kg in air and 0.88 kg in water. The density of the steel is
7.71 x103 kg/m3 and of water is103 kg/m3. The cube
(1) Must be solid
(2) Consists of impure steel
(3) Must be hollow
(4) Consists of pure steel
Ans. (4)

...............................................-----------------------------------................................................

Physics SAMPLE PAPER FOR PMT PET
solved physics Sample paper for PMT PET CBSE
PMT Sample Papers Free Online

1. The Prongs of a vibrating tuning fork are immersed in water. Then
(1) Amplitude of the waves decreases
(2) Velocity of the waves decreases
(3) Frequency of the waves decreases
(4) Wavelength of the waves increases
Ans. (c)

2. In which of the following situations will there be no force?
(1) A positive charge projected passes a piece of soft iron
(2) A positive charge sent along the axis of a solenoid
(3) Two parallel wires carrying current in the same direction
(4) A positive charge projected between the poles of a magnet.
Ans. (a)

3. A nuclide A undergoes ct-decay and another nuclide B undergoes 3-decay.
(1) All the a-particles emitted by A will have almost the same speed
(2) The a-particles emitted by A may have widely different speeds
(3) All the n-particles emitted by B will have almost the same speed
(4) The n-particles emitted by B may have widely different speeds.
Ans. (c)

4. The meniscus of a liquid obtained in one of the limbs of a narrow U-tube is held in an electromagnet with the meniscus in line with the field. The liquid is seen to rise. This indicates that the liquid is
(1) Paramagnetic
(2) Ferromagnetic
(3) Diamagnetic
(4) Non-magnetic
Ans. (a)

5. In an n-p-n transistor circuit, the collector current is 10 mA. If 90% of the electrons are able to reach the collector:
(1) The emitter current will be 9 mA
(2) The emitter current will be 11 mA
(3) The base current will be 1 mA
(4) The base current will be 0.1 mA
Ans. (b)

6. If an increasing temperature, the resistance decreases, then it is
(1) Superconductor
(2) Semiconductor
(3) Insulator
(4) None of these
Ans. (b)

Directions: In the following questions more than one of the answers given may be correc4. Select the correct answers and mark it according to the code.
Code:
(a) 1 and 2 are correct
(b) 2 and 3 are correct
(c) 1 and 4 are correct
(d) 1, 2 and 3 are correct

7. The charge flowing in a conductor varies with time as Q = at — bt2 then the current:
(1) Reaches a maximum and then decreases
(2) Falls to zero after t = a/ 2b
(3) Changes at the rate of (—2b)
(4) Will remain constant
Ans. (b)

8. In Seeback series, antimony appears after bismuth. But in Sb-Bi thermocouple the current flows from:
(1) Bi to Sb through hot junction
(2) Bi to Sb through cold junction
(3) Sb to Bi through hot junction
(4) Sb to Bi through cold junction
Ans. (c)

9. A ray of light traveling in a transparent medium falls on a surface separating the medium from air at an angle of incidence 450 The ray undergoes total internal reflection. If n is the refractive index of the medium with respect to air, select the possible value of n from the following:
(1) 1.3
(2) 1.4
(3) 1.5
(4) 1.6
Ans. (c)

10. In the Young’s double slit experiment, the interference pattern is found to have an intensity ratio between bright and dark fringes as 9. This implies that:
(1) The intensities at the screen due to the two slits are 4 units and 1 unit respectively
(2) The intensities at the screen due to two slits are 5 units and 4 units respectively
(3) The amplitude ratio is 3
(4) The amplitude ratio is 2
Ans. (a)

........................................................----------------------------------------....................................

Basic Physics Model questions for exams
Physics Model Questions and Practice Exam
sample question paper of basic physics
1. A hammer weighing 3 kg, moving with a velocity of 10 m/s, strikes against the head
of a spike and drives it into a block of wood. If the hammer comes to rest in 0.025 s,
the impulse associated with the ball will be
(a) 30Ns
(b)-30Ns
(c) l5Ns
(d)-l5Ns
Ans. (b)

2. In the above problem, the average (retarding) force acting on the spike will be
(a) 600 N
(b)-600 N
(c) 1200 N
(d)-1200N
Ans. (d)

3. When a bicycle travels on rough surface, its speed
(a) increases
(b) decreases
(c) remains the same
(d) none of these
Ans. (b)

4. It is difficult to walk on ice because of
(a) absence of friction
(b) absence of inertia
(c) more inertia
(d) more friction
Ans. (a)

5. The law which gives a quantitative measurement of force is
(a) Newton’s third law of motion
(b) Newton’s first law of motion
(c) Newton’s second law of motion
(d) Newton’s law of gravitation
Ans. (c)

6. External forces
(a) are always balanced
(b) never balanced
(c) may or may not be balanced
(d) none of these
Ans. (c)

7. A and B are two objects with mass 6 kg and 34 kg respectively. Then
(a) A has more inertia than B
(b) B has more inertia than A
(c) A and B both have same inertia
(d) none of the above is true
Ans. (b)

8. Which of the following class of forces different from others?
(a) Magnetic force
(b) Electhcal force
(c) Gravitational force
(d) Stretching of a spring
Ans. (d)

9. A body is said to be under balanced forces when the resultant force acting on the
body is
(a) unity
(b) zero
(c) infinite
(d) none of these
Ans. (b)

10. If g = 10 ms-2, what is the force of gravity acting on a mass of 1 kg?
(a) 1 N
(b) 10 N
(c) 1 N
10
(d) none of these
Ans. (b)

11. A force acts on an object which is free to move. If we know the magnitude of the
force and the mass of the object, newton’s 2nd law of motion enables us to determine
the object’s
(a) weight
(b) speed
(c) acceleration
(d) position
Ans. (c)

12. When a force of 1 newton acts on a mass of 1 kg that is able to move freely, the
object moves with a/an
(a) speed of 1 ms-1
(b) acceleration of 1 ms-2
(c) speed of 1 kms-1
(d) acceleration of 10 ms-2
Ans. (b)

13. Newton used the phrase ‘quantity of motion’ for
(a) momentum
(b) force
(c) acceleration due to gravity
(d) none of these
Ans. (a)

14. kg ms-1 is the SI unit of
(a) impulse
(b) force
(c) angular velocity
(d) none of these
Ans. (a)

15. The gravitational unit of force in the metric system is
(a) g wt
(b) N
(c) kg wt
(d) none of these
Ans. (c)

16. Frictional force can’t be measured in
(a) kg wt
(b) newton
(c) dyne
(d) kg ms-1
Ans. (d)

17. Graphite powder is used in machines to
(a) enhance friction
(b) enhance profit
(c) reduce friction
(d) reduce efficiency
Ans. (c)

18. Friction is a/an
(a) self-adjusting force
(b) necessary evil
(c) important force in daily life
(d) all the above
Ans. (d)

19. A cannon after firing recoils due to
(a) conservation of energy
(b) backward thrust of gases produced
(c) Newton’s 1st law of motion
(d) Newton’s 3rd law of motion
Ans. (d)

20. You are marooned on a frictionless horizontal surface and cannot exert any
horizontal force by pushing against the surface. How can you get off?
(a) By jumping.
(b) By spitting or sneezing.
(c) By rolling your body on the surface.
(d) By running on the plane.
Ans. (b)

..............................................-----------------------------------------.....................................

free physics objective test
Free Physics Online Practice Test
Free Online Mock Multiple Choice Question Practice Test Exam in physics
Advanced High School Physics Tests – Multiple Choice

1. When uranium ( ₉₂U₂₃₈ ) decays to lead (₈₂ Pb²⁰⁶), number of ?-particles and ?-particles emitted are:

(a) 6 and 6 respectively

(b) 8 and 8 respectively

(c) 6 and 8 respectively

(d) 8 and 6 respectively

Ans. (d)

2. When an electron jumps from a level n = 4 to n = 1, the momentum of recoiled hydrogen atom will be:

(a) 6.8 x 10^-27 kg m/s

(b) 12.75 x 10^-19 kg m/s

(c) 13.6 x 10^-19 kg m/s

(d) zero

Ans. (a)

3. Which level of doubly ionised (Li³⁺ ) ion has the same energy as the ground state energy of the hydrogen atom?

(a) n=2

(b) n=3

(c) n=4

(d) n=9

Ans. (a)

4. A body of mass m thrown horizontally with velocity v, from the top of tower of height h touches the level ground at a distance of 250 m from the foot of the tower. A body of mass 2m thrown horizontal with a velocity v/2 from the top of the tower of height 4h will touch the level ground at a distance from the foot of the tower.

(a) 250 m

(b) 50 m

(c) 125 m

(d) 50?2m

Ans. (a)

5. A body of mass 6 kg moves in a straight line according to the equation x = — 75t where x denotes the distance in metres and t the time in seconds. The force on the body at t = 4 s is:

(a) 64 N

(b) 72 N

(c) 144 N

(d) 36 N

Ans. (c)

6. The source of magnetic field is:

(1) Isolated magnetic pole

(2) Current loop

(3) Static electric charge

(4) Micrometer

Ans. (a)

7. The sides of a rectangle are 6.01 m and 12 m. Taking the significant figures into account, the area of the rectangle is

(a) 72.12m²

(b) 7.2m²

(c) 72.1m²

(d) 72m²

Ans. (d)

8. A ball moving with a velocity of 5 m/s impinges on a fixed plane at an angle of 45°, its direction after impact is equally inclined to the line of impact. If coefficient of restitution is 0.5, the velocity of ball after impact will be:

(a) 0.5 m/s

(b) 1.5 m/s

(c) 2.5 m/s

(d) 3.5 m/s

Ans. (c)

9. Two protons more parallel to each other with equal speeds 9 x 10⁵ m/s. The ratio of magnetic force and electrical force between them is

(a) 9 x 10^-9

(b) 9 x 10^-6

(c) 9 x 10^-3

(d) 1/9 x 10⁶

Ans. (b)

10. Two astronauts have deserted their spaceship in a region of space far from the gravitational attraction of any other body. Each has a mass of 100 kg and they are 100 m apart. They are initially at rest relative to one another. How long will it be before the gravitational attraction brings them 1 cm closer together?

(a) 2.52 days

(b) 1.41 days

(c) 0.70 days

(d) 1.41 s

Ans. (b)

11. A particle under the action of an SHM has a period 3s and under the effect of another it has a period 4 s. What will be its period under the combined action of both he two simple harmonic motions in the same direction?

(a) 7 s

(b) 5 s

(c) 2.4 s

(d) 0.4 s

Ans. (c)

12. Half a mole of helium at 27°C and at a pressure of 2 atm is mixed with 1.5 moles of N2 at 77°C and at a pressure of 5 atm, so that the volume of the mixture is equal to the sum of their initial volumes. If the temperature of the mixture is 69°C, its pressure in atmospheres is:

(a) 3.5

(b) 3.8

(c) 2.95

(d) 4.25

Ans. (b)

13. An electron (e/m = 1.76 x 10¹¹ C / kg) enters a region, where there is a uniform magnetic field of induction 1.78 x 10^-3 T with a velocity 4 x 10⁶ m/s in a direction 60° with the field. The pitch (in cm) of its helical path in the region is:

(a) 3.2 cm

(b) 4 cm

(c) 7.4 cm

(d) 6.0 cm

Ans. (b)

14. The coercivity of a bar magnet is 120 A/m. It is to be demagnetised by placing it inside a solenoid of length 120 cm and number of turns 72. The current flowing through the solenoid is:

(a) 0.5 A

(b) 1 A

(c) 2 A

(d) 4 A

Ans. (c)

15. Two solid spheres of radii R₁ and R₂ are heated to same temperature and allowed to cool under similar conditions. Their rates of cooling are in the ratio of:

(a) R₁/R₂

(b) R₂/R₁

(c) R₂²/R₁²

(d) R₁²/ R₂²

Ans. (a)

16. Bells are made of metal and not of wood because:

(a) the thermal conductivity of metal is greater than that of wood

(b) the density of the metal is greater than that of wood

(c) the sound is not conducted by metals but is radiated

(d) wood dampers vibrations while metals are elastic

Ans. (d)

17. Two tuning forks of frequencies 256 and 258 vib/s are sounded together. Then the time interval between two consecutive maxima heard by an observer is:

(a) 2 s

(b) 0.5 s

(c) 250 s

(d) 252 s

Ans. (b)

18. An achromatic convergent lens of focal-length

+ 20 cm is made of two lenses (in contact) of materials having dispersive powers in the ratio of 1 : 2 and having focal length f₁ and f₂. Which of the following is true?

(a) f₁ = 10 cm, f₂ = -20 cm

(b) f₁ = 20 cm, f₂ = 10 cm

(c) f₁ = 10 cm, f₂ = -20 cm

(d) f₁ = -20cm, f₂ = -l0 cm

Ans. (a)

19. For observing cricket match a binocular is preferred to a terrestrial telescope because:

(a) the binocular gives the proper three dimensional views

(b) the binocular has a shorter wavelength

(c) the telescope does not give erect image

(d) telescope has chromatic aberrations

Ans. (a)

20. The speed of rotation of a fan is reduced by putting a rheostat in series with the fan. Let us say the supply is DC for converience. We consume:

(a) the same power than at full speed

(b) more power than at full speed

(c) less power than at full speed but less efficiency

(d) less power than at full speed but more efficiency

Ans. (c)

21. Two insulated charged spheres of radii 20 cm and 25 cm respectively and having an equal charge Q are connected by a copper wire and then they are separated. The correct inference is:

(a) both the spheres will have the same charge Q

(b) charge on the 20 cm sphere will be greater than that of the 25 cm sphere

(c) charge on the 25 cm sphere will be greater than that on the 20 cm sphere

(d) charge on each of the sphere will be 2?

Ans. (c)

22. In the measurement of resistance by a metre bridge, the current is necessarily reversed through the bridge wire to eliminate:

(a) end error

(b) the index error

(c) error due to 4iermoelectric effects

(d) random error

Ans. (a)

23. For light of wavelength 5000 Å photon energy is nearly 2.5 eV. For X-rays of wavelength 1 Å, the photon energy will be close to

(a) (2.5 ÷ 5000) eV

(b) (2.5 ÷ (5000)2) eV

(c) (2.5 x 5000) eV

(d) (2.5 x (5000)2) eV

Ans. (c)

24. Fast neutrons can easily be slowed down by:

(a) the use of lead shielding

(b) passing them through heavy water

(c) elastic collision with heavy nuclei

(d) applying strong magnetic field

Ans. (b)

25. Uranium ores contain one radium 226 atom for energy 2.8 x 10⁶ uranium -238 atom. The half-life of ₉₂U²³⁸ if the half-life of ₈₈Ra²²⁶ is 1600 year is (₈₈Ra²²⁶ is a decay product of ₉₂U²³⁸ ):

(a) 1.75 x10³ year

(b) 1600 x 238/92 year

(c) 4.5 x 10⁹ year

(d 1600 x 92/238 year

Ans. (c)

26. X-rays and y-rays of the same energies may be distinguished by:

(a) their velocity

(b) their ionising power

(c) their intensity

(d) method of production

Ans. (d)

27. Light from a hydrogen discharge tube is made incident on the cathode of a photoelectric cell. The work function of the cathode surface is 3.1 eV. In order to reduce the photoelectric current to zero value, the minimum potential applied to anode with respect to cathode should be:

(a) -3.1V

(b) +10.5V

(c) -16.7 V

(d) -10.5 V

Ans. (d)

28. For cubic lattice:

(a) the sc has the lowest packing fraction

(b) the bcc has the lowest packing fraction

(c) the bcc has the highest packing fraction

(d) the fcc has the lowest packing fraction

Ans. (a)

29. A region is specified by potential function V = 5x + 4y – 6z, then potential gradient is:

(a) 5i + 4j – 6k

(b) 5i + 4j + 6k

(c) – 5i – 4j + 6k

(d) – 5i + 4j – 6k

Ans. (a)

30. In order to find time, an astronaut orbiting in earth’s satellite should use:

(a) pendulum clock

(b) a watch having a main string to keep it going

(c) either a pendulum clock or a spring watch

(d) neither a pendulum clock nor a spring watch

Ans. (b)

31. Two gases X and Y having the same temperature T, the same pressure P and the same volume V are mixed. If the mixture has the volume V and temperature T, then the pressure of the mixture must be

(a) P/2

(b) P

(c) 2P

(d) 4P

Ans. (c)

32. A person can see objects only at distance greater than 40 cm. He is advised to use lens of power:

(a) – 2.SD

(b) + 2.5D

(c) – 6.25D

(d) + 1.5D

Ans. (d)

33. The dielectric constant k of an insulator cannot be:

(a) 3

(b) 6

(c) 8

(d) infinite

Ans. (d)

34. Two gases X and Y having the same temperature T, the same pressure P and the same volume V are mixed. If the mixture has the volume V and temperature T, then the pressure of the mixture must be

(a) P/2

(b) P

(c) 2P

(d) 4P

Ans. (c)

35. Three bulbs rated 25 W, 40 W, 60 W are designed to work on 220 V AC mains.. Which of these bulbs will burn most brightly, if they are connected in series across 220 V mains?

(a) 25W

(b) 40W

(c) 60W

(d) All will burn equally bristly

Ans. (a)

36. Lines of force due to earth’s horizontal magnetic field are:

(a) parallel and straight

(b) concentric circles

(c) elliptical

(d) curved lines

Ans. (a)

37. In which one of the following regions of the electromagnetic spectrum, will the vibration motion of molecules give rise to absorption?

(a) Ultraviolet

(b) Microwaves

(c) Infrared

(d) Radiowaves

Ans. (d)

38. If the forward voltage in p- n junction is increased, the length of depletion layer will:

(a) increase

(b) decrease

(c) remain unchanged

(d) disappear

Ans. (b)

39. In an extrinsic semiconductor, the ratio of impurity atoms to pure atoms is:

(a) 1 : 10⁸

(b) 10⁸ : 1

(c) 1 : 10⁶

(d) 10⁶ : 1

Ans. (c)

40. If the radius of earth of R then the 1height h at which the value of g becomes one fourth, will be:

(a) R/8

(b) 3R/8

(c) 3R/4

(d) R/2

Ans. (b)

 ..................................-------------------------------------------------................................................

AIEEE Physics Free practice online
Free Physics Online Practice Tests
Free Online Aieee Physics Test Practice and Preparation Test
AIEEE – Free Online AIEEE Physics Test

1. 16 cm³ of water flows per second through a capillary tube of radius a cm and of length land when connected a pressure head of H cm of water. If a tube of same length and radius a/2 cm is connected to the same pressure head the quantity of water flowing through the tube per second is

(a) 8cm³

(b) 1cm³

(c) 16 cm³

(d) 4 cm³

Ans. (b)

2. Pressure inside two soap bubbles are 1.01 and 1.03 atm. Ratio between their volumes is:

(a) 27:1

(b) 3:1

(c) 127:101

(d) None of these

Ans. (a)

3. A stationary object at 4°C and weighing 3.5 kg falls from a height of 2000 m on a snow mountain at 0°C. If the temperature of the object just before hitting the snow is 0°C and the object comes to rest immediately (g = 10 rn/s² and latent heat of ice = 3.5 x 10⁵ J/s) , then the object will melt:

(a) 2 kg of ice

(c) 20 g ice

(b) 200 g of ice

(d) 2 g ice

Ans. (b)

4. A Carnot enging works between temperatures 727°C and 27° C. The efficiency of the engine is:

(a) 70%

(b) 30%

(c) 0%

(d) 10%

Ans. (a)

5. A sphere at temperature 600 K is placed in environment of temperature 200 K. Its cooling rate is H. If the temperature is reduced to 400 K, then the cooling in same environment will be:

(a) H/16

(b) (9/27) H

(c) (16/3) H

(d) (3/16) H

Ans. (d)

6. An ideal gas at 27° C is compressed adiabatically to 8/27 of its original volume if

y = 5/3, then rise in temperature is:

(a) 405 K

(b) 225K

(c) 375 K

(d) 450 K

Ans. (c)

7. The root means square velocity of the molecules in a sample of helium 5/7th that of the molecules in a sample of hydrogen at 0°C. Then, the temperature of helium sample is about

(a) 100° C

(b) 273°C

(c) OK

(d) 0°C

Ans. (d)

8. The displacement of the particle from its mean position (in meter) varies with time (in second) according to the equation: y = 0.2 sin (l0?t + L57?) cos (l0?t + 1.5?). The motion of the particle is

(a) Along a circular path

(b) Simple harmonic motion with time period 0.1 S

(c) No simple harmonic motion

(d) Simple harmonic motion with time period 0.2s

Ans. (b)

9. Light of frequency 8 x 10¹⁵ Hz is incident on a substance of photoelectric work function 6.125 eV. The maximum kinetic energy of the emitted photoelectrons will be

(a) 39 eV

(b) 27 eV

(c) 54eV

(d) 13.5eV

Ans. (b)

10. A cylindrical tube, open at both ends has a fundamental frequency f in air. The tube dipped vertically in water, so that half of it is in water, the fundamental frequency of the air column is now:

(a) 2f

(b) f

(c) 3f/4

(d) f/2

Ans. (b)

11. The distance between two points difference in phase by 60° on a wave having a wave velocity 360 m/s and frequency 500 Hz is:

(a) 0.36m

(b) 0.12m

(c) 0.18m

(d) 0.72m

Ans. (b)

12. The heat generated in a circuit is dependent upon the resistance, current and time for which the current is flown. If the error in measuring. The above are 1%, 2% and 1% respectively. The maximum error in measuring the heat is

(a) 8%

(b) 6%

(c) 18%

(d) 12%

Ans. (b)

13. A particle having charge 100 times that of an electron is revolving in a circular path of radius 0.8 m with one rotation per second. The magnetic field produced at the centre will be

(a) 10^-17 µ₀

(b) 10^-11 µ₀

(c) 10^-7 µ₀

(d) 10^-3 µ₀

Ans. (a)

14. The energy of an X-ray photon is 2 keV, then its frequency will be:

(a) 3.2 x l0^-6 per sec

(b) 5×10¹⁷per sec

(c) 2 x 10¹⁷ per sec

(d) 2 x l0¹⁸ per sec

Ans. (b)

15. A refracting angle of a prism is A and the refractive index of the prism is cot (A/2) Then, angle of minimum deviation is:

(a) 180° – 2A

(b) 90° – A

(c) 180° + 2A

(d) 180° – 3A

Ans. (a)

16. If the critical angle for total internal reflection from medium to vacuum is 30°. The velocity in the medium will be:

(a)√3 x 10⁸ m/s

(b) 6 x 10⁸ m/s

(c) 1.5 x 10⁸ m/s

(d) 3 x 10⁸ m/s

Ans. (c)

17. The length of an astronomical telescope adjusted for parallel light is 100 cm. If the magnification of the telescope is 19. The focal length of two lenses, i.e., objective and eye piece are

(a) 76 cm and 4 cm

(b) 95 cm and 5 cm

(c) 85 cm and 15 cm

(d) 82 cm and 18 cm

Ans. (b)

18. Doubly ionised helium atoms and hydrogen ions are accelerated from rest through the same potential drop. The ratio of the final velocities of helium and the hydrogen ions are:

(a) 1/2

(b) 1/√2

(c)√2

(d) 2

Ans. (b)

19. In a transformer, the number of turns of primary coil and secondary coil are 5 and 4 respectively. If 220 V is applied on the primary coil, then the ratio of primary current to the secondary current will be

(a) 9:5

(b) 5:9

(c) 5:4

(d) 4:5

Ans. (d)

20. If the distance between parallel plates of a capacitor is halved and dielectric constant is doubled then the capacitance will

(a) Remain the same

(b) Increase 4 times

(c) Increase 2 times

(d) Decrease 2 times

Ans. (b)

21. In a nuclear fission, 0.1% mass is converted into energy. The energy released by the fission of 1 kg mass will be:

(a) 9 x 10¹⁹ J

(b) 9 x 10¹⁷ J

(c) 9 xl0¹⁶ J

(d) 9 xl0¹³ J

Ans. (d)

22. The energy of hydrogen atom in the nth orbit is E_n, then the energy in the nth orbit of single ionised helium atom is:

(a) E_n/2

(b) 2E_n

(c) 4E_n

(d) E_n/4

Ans. (c)

23. Force between two identical bar magnets whose centres r metre apart is 4.8 N when their axis are in the same line. If the separation is increased to 2 r metres, the force between them is reduced to

(a) 0.3N

(b) 0.6N

(c) 2.4N

(d) 1.2N

Ans. (a)

24. An air capacitor of capacity C = 10 µF is connected to a constant voltage battery of 12 V. Now, the space between the plates is filled with a liquid of dielectric constant 5. The additional charge that flows now from battery to the capacitor is

(a) 24 µC

(b) 480 µC

(c) 600 µC

(d) 120 µC

Ans. (b)

25. Pure silicon at 300 K has equal electrons n_e and holes h concentration of                  1.5 x 10¹⁶/m3. Doping by indium increases number of holes h to 4.5 x 10²²/m3 then n_e ‘doped in silicon will be:

(a) 3.0x 10^-19/m³

(b) 5×10⁹/m³

(c) 4.5×10²²/m³

(d) 1.5xl0¹⁶/m³

Ans. (b)

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1. 10 g of radioactive material of half-life 15 year is kept in a store for 20 year, then the disintegrated material will be:

(a) 12.6g

(b) l0g

(c) 4.02 g

(d) 6.04g

Ans. (d)

2. A ray of light falls on a transparent glass slab of refractive index 1.62. If the reflected and refracted rays are mutually perpendicular, then the value of angle of incidence will be:

(a) 58.3°

(b) 68.3°

(c) 48.3°

(d) 78.3°

Ans. (a)

3. A slit of width 0.15 cm is illuminated by light wavelength  and a diffraction pattern is obtained on a screen 2.1 m away. The width of the central maxima will be:

(a) 0.24m

(b) 0.14m

(c) 0.28 m

(d) None of these

Ans. (b)

4. The dispersive powers of crown and flint glasses are 0.02 and 0.04 respectively. The focal length of the two components of an achromatic doublet of focal length 20 cm will be:

(a) 10 cm, -20 cm

(b) 20 cm, -40 cm

(c) 30 cm, -60 cm

(d) None of these

Ans. (a)

5. Two whistles A and B have frequencies 660 Hz and 590 Hz respectively. An observer is standing in the middle of line joining the two sources. Source B and observer are moving towards tight with velocity 30 m/s and A is standing on left side. If the velocity of sound in air is 300 m/s. The number of beats listened by the observer are:

(a) 8

(b) 6

(c) 4

(d) 2

Ans. (c)

6. The ionisation potential of hydrogen atom is13.6 V. In the lowest energy level, this atom is ionised by absorbing a photon of 800 Å. The kinetic energy of the emitted electron will be:

(a) 2.91eV

(b) 1.91eV

(c) 3.82 eV

(d) None of these

Ans. (a)

7. When n-type semiconductor is heated, the number of:

(a) Electrons increases, holes decreases

(b) Holes increases, electrons decreases

(c) Electrons and holes increases equally

(d) Electrons and holes remain same

Ans. (a)

8. A black body at a high temperatures K radiates energy at the rate of E, W/m2. When the temperature falls T/2 K, the radiated energy is:

(a) E/24

(b) 2E

(c) E/16

(d) E/4

Ans. (c)

9. Mercury thermometer can be used to measure the temperature upto

(a) 500°C,

(b) 360°C

(c) 260°C

(d) 200°C

Ans. (b)

10. In an interference pattern by two identical slits, the intensity of central maxima is 1. What will be the intensity of the same spot, if one of the slit is closed?

(a) 21

(b) 1/8

(c) 1/2

(d) 1/4

Ans. (d)

11. A wire of length of 0.5 m and carrying a current of 1.2 A is placed in a uniform magnetic field of induction 2 T. If the magnetic field of perpendicular to the length of the wire, then the force on the wire will be:

(a) 4.2N

(b) 3.5N

(c) 1.2 N

(d) 0.8 N

Ans. (c)

12. A convex lens is making full image of an object. If half of lens is covered by an opaque object, then:

(a) Full image of decreased intensity is seen

(b) Half image of same intensity is seen

(c) Full image of same intensity is seen

(d) Half image of not seen

Ans. (a)

13. If two lenses pf power +2.OD and L5D are placed in contact, then the effective power of the combination will be:

(a) 8.4D

(b) 3.5D

(c) 7.0 D

(d) None of these

Ans. (b)

14. When a radioactive substance emits an α-particle, its position in the periodic table is lowered by:

(a) 4 places

(b) 3 places

(c) 2 places

(d) 1 places

Ans. (c)

15. Electromotive force is the force which is able to maintain a constant:

(a) Potential difference

(b) Power

(c) Resistance

(d) Current

Ans. (a)

16. The periodic time of a body executing simple harmonic motion is 3s. After how much interval from time t = 0, its displacement will be half of its amplitude?

(a) 1/8s

(b) 1/6s

(c) 1/4s

(d) 1/3s

Ans. (c)

17. A step-up transformer has transformation ratio of 3: 2. What is the voltage in the secondary, if the voltage in the primary is 30 V?

(a) 360 V

(b) 90 V

(c) 45V

(d) 35V

Ans. (c)

18. When air is replaced by a dielectric medium of constant K. The maximum force of attraction between two charges separated by a distance:

(a) Increases  times

(b) Increases K times

(c) Decreases K times

(d) Remains constant

Ans. (c)

19. Two inductors each of inductance L are joined in parallel. What is their equivalent inductance?

(a) 0

(b) L/2

(c) L

(d) 2L

Ans. (b)

20. A thin uniform circular ring is rolling down on an inclined plane of inclination 30° without slipping. Its linear acceleration along the inclined plane is:

(a) 2g/3

(c) g/4

(b) g/3

(d) g/2

Ans. (b)

21. What is the voltage gain in a common base amplifier, where input resistance is 3Ω and load resistance is 24Ω ? (Take α = 0.6)

(a) 1.2

(c) 4.8

(b) 2.4

(d) 8.16

Ans. (c)

22. Minimum excitation potential of Bohr’s first orbit in hydrogen atom will be:

(a) 3.4V

(b) 3.6V

(c) 10.2V

(d) 134V

Ans. (c)

23. A battery of 10 V and internal resistance 0.5Ω is connected across a variable resistance R. The value of R for which the power delivered in its maximum state, is equal to:

(a) 0.5Ω

(b) 1Ω

(c) 1.5Ω

(d) 2Ω

Ans. (a)

24. An electron beam moving with uniform velocity is gradually’ diverging. When it is accelerated to a very high velocity, it:

(a) Diverges

(b) Converges

(c) First diverges and then converges

(d) Does not show any of the effects

Ans. (b)

25. A tube closed at one end containing air produces fundamental note of frequency 250 Hz. If the tube is opened at both ends, the fundamental frequency will be:

(a) 1000 Hz

(b) 500 Hz

(c) 250 Hz

(d) 300 Hz

Ans. (b)

26. A body is projected at an angle 30° to the horizontal. The kinetic energy of the body at the highest point in its flight will be:

(a) 1/2 K

(c) 3/4K

(b) K/4

(d) None of these

Ans. (b)

27. Two stones of masses 4 kg and 8 kg are moving with velocities 4 m/s and 20 m/s towards each other due to mutual gravitation attraction the velocity of their centre of mass will be:

(a) 24.9 m/s

(b) 28.14 m/s

(c) 14.7 m/s

(d) 7 m/s

Ans. (c)

28. Two bodies of masses m and 16 m are moving with equal kinetic energy. Then the ratio of their linear momentum will be:

(a) 1:2

(b) 1:8

(c) 1:1

(d) 1:4

Ans. (d)

29. The total energy of a particle is twice its rest energy. Then its speed will be:

(a) 1.86 c

(b) 0.433 c

(c) 0.866 c

(d) None of these

Ans. (c)

30. A sample of a radioactive substance contains 2828 atoms. If its half- life is 2 days, how many atoms will be left intact in the sample after one day?

(a) 1000

(c) 707

(b) 2000

(d) 1414

Ans. (b)

31. In a n-p-n transistor circuit the collector current is 9 mA. If 90% of the electrons emitted reach the collector, then the emitter current is:

(a) 8.lmA

(b) 8mA

(c) 9 mA

(d) 10 mA

Ans. (d)

32. The dimensional formula for Plancks constant and angular momentum is:

(a) [ML²T²] and [MLT^-1]

(b) [ML²T^-1] and [ML²T^-1]

(c) [ML³T¹] and [ML²T^-2]

(d) [MLT^-1] and [MLT^-2] ‘

Ans. (b)

33The speed of the system after collision, is

(a) 3u

(b) u/3

(c) 2u

(d) u/4

Ans. (b)

34 A wet open umbrella is held vertical and it whirled about the handle at a uniform rate of 21 revolutions in 44 s. If the rim of the umbrella is a circle of 1. m in dimeter and the height of the rim above the flour is 4.9 m, the locus of the drop is a circle of radius

(a) √2.5 m

(b) 1 m

(c) 3 m

(d) 1.5 m

Ans. (a)

35. The moment of inertia of a body about a given axis is 1.2 kg- m². To produce a rotational kinetic energy of 1500 J an angular acceleration of 25 rad /s² must be applied for:

(a) 8.5 s

(b) 5s

(c) 2 s

(d) 1 s

Ans. (c)

36. An earth satellites S has an orbit radius which is 4 times that of communication satellite C. The period of revolution of S will be:

(a) 32 day

(b) 18 days

(c) 8 days

(d) 9 days

Ans. (c)

37. n small balls, each of mass m impinge elastically each second on a surface with a velocity u, then the force experienced by the surface in one second, will be

(a) 4 mnu

(b) 2 mnu

(C) 1.5mnu

(d) 0.8mnu

Ans. (b)

38. An object of mass 40 kg and having a velocity 4 m/s collides with another object     (m = 60 kg)having velocity 2 m/s. The collision is perfectly inelastic. The loss in energy is

(a) 110 J

(b) 48 J

(c) 392 J

(d) 440 J

Ans. (b)

39. Dimensions of surface tension are:

(a) [M²L²T²]

(b) [M²LT²]

(c) [MT²]

(d) [MLT²]

Ans. (c)

40. An iron rod of length 2 m and area of cross-section 50 mm2 stretches by 0.5 mm, when a mass of 250 kg is hung from its lower end. The Young’s modulus of iron rod is:

(a) 19.6×10²⁰N/m²

(b) 19.6×10¹⁸N/m²

(c) 19.6 xI0¹⁵ N/m²

(d) 19.6 x10¹⁰N/m²

Ans. (d)

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1. The dimensional formula for Plancks constant and angular momentum is:

(a) [ML²T²] and [MLT^-1]

(b) [ML²T^-1] and [ML²T^-1]

(c) [ML³T¹] and [ML²T^-2]

(d) [MLT^-1] and [MLT^-2] ‘

Ans. (b)

2. A body of mass m moving with velocity u collides with a stationary body of mass 2 m. The speed of the system after collision, is

(a) 3u

(b) u/3

(c) 2u

(d) u/4

Ans. (b)

3. A wet open umbrella is held vertical and it whirled about the handle at a uniform rate of 21 revolutions in 44 s. If the rim of the umbrella is a circle of 1. m in dimeter and the height of the rim above the flour is 4.9 m, the locus of the drop is a circle of radius

(a)√2.5 m

(b) 1 m

(c) 3 m

(d) 1.5 m

Ans. (a)

4. The moment of inertia of a body about a given axis is 1.2 kg- m². To produce a rotational kinetic energy of 1500 J an angular acceleration of 25 rad /s² must be applied for:

(a) 8.5 s

(b) 5s

(c) 2 s

(d) 1 s

Ans. (c)

5. An earth satellites S has an orbit radius which is 4 times that of communication satellite C. The period of revolution of S will be:

(a) 32 day

(b) 18 days

(c) 8 days

(d) 9 days

Ans. (c)

6. n small balls, each of mass m impinge elastically each second on a surface with a velocity u, then the force experienced by the surface in one second, will be

(a) 4 mnu

(b) 2 mnu

(C) 1.5mnu

(d) 0.8mnu

Ans. (b)

7. An object of mass 40 kg and having a velocity 4 m/s collides with another object     (m = 60 kg)having velocity 2 m/s. The collision is perfectly inelastic. The loss in energy is

(a) 110 J

(b) 48 J

(c) 392 J

(d) 440 J

Ans. (b)

8. Dimensions of surface tension are:

(a) [M²L²T²]

(b) [M²LT²]

(c) [MT²]

(d) [MLT²]

Ans. (c)

9. An iron rod of length 2 m and area of cross-section 50 mm2 stretches by 0.5 mm, when a mass of 250 kg is hung from its lower end. The Young’s modulus of iron rod is:

(a) 19.6×10²⁰N/m²

(b) 19.6×10¹⁸N/m²

(c) 19.6 xI0¹⁵ N/m²

(d) 19.6 x10¹⁰N/m²

Ans. (d)

10. 16 cm³ of water flows per second through a capillary tube of radius a cm and of length land when connected a pressure head of H cm of water. If a tube of same length and radius a/2 cm is connected to the same pressure head the quantity of water flowing through the tube per second is

(a) 8cm³

(b) 1cm³

(c) 16 cm³

(d) 4 cm³

Ans. (b)

11. Pressure inside two soap bubbles are 1.01 and 1.03 atm. Ratio between their volumes is:

(a) 27:1

(b) 3:1

(c) 127:101

(d) None of these

Ans. (a)

12. A stationary object at 4°C and weighing 3.5 kg falls from a height of 2000 m on a snow mountain at 0°C. If the temperature of the object just before hitting the snow is 0°C and the object comes to rest immediately (g = 10 rn/s² and latent heat of ice = 3.5 x 10⁵ J/s) , then the object will melt:

(a) 2 kg of ice

(c) 20 g ice

(b) 200 g of ice

(d) 2 g ice

Ans. (b)

13. A Carnot enging works between temperatures 727°C and 27° C. The efficiency of the engine is:

(a) 70%

(b) 30%

(c) 0%

(d) 10%

Ans. (a)

14. A sphere at temperature 600 K is placed in environment of temperature 200 K. Its cooling rate is H. If the temperature is reduced to 400 K, then the cooling in same environment will be:

(a) H/16

(b) (9/27) H

(c) (16/3) H

(d) (3/16) H

Ans. (d)

15. An ideal gas at 27° C is compressed adiabatically to 8/27 of its original volume if

y = 5/3, then rise in temperature is:

(a) 405 K

(b) 225K

(c) 375 K

(d) 450 K

Ans. (c)

16. The root means square velocity of the molecules in a sample of helium 5/7th that of the molecules in a sample of hydrogen at 0°C. Then, the temperature of helium sample is about

(a) 100° C

(b) 273°C

(c) OK

(d) 0°C

Ans. (d)

17. The displacement of the particle from its mean position (in meter) varies with time (in second) according to the equation: y = 0.2 sin (l0∏t + L57∏) cos (l0∏t + 1.5∏). The motion of the particle is

(a) Along a circular path

(b) Simple harmonic motion with time period 0.1 S

(c) No simple harmonic motion

(d) Simple harmonic motion with time period 0.2s

Ans. (b)

18. Light of frequency 8 x 10¹⁵ Hz is incident on a substance of photoelectric work function 6.125 eV. The maximum kinetic energy of the emitted photoelectrons will be

(a) 39 eV

(b) 27 eV

(c) 54eV

(d) 13.5eV

Ans. (b)

19. A cylindrical tube, open at both ends has a fundamental frequency f in air. The tube dipped vertically in water, so that half of it is in water, the fundamental frequency of the air column is now:

(a) 2f

(b) f

(c) 3f/4

(d) f/2

Ans. (b)

20. The distance between two points difference in phase by 60° on a wave having a wave velocity 360 m/s and frequency 500 Hz is:

(a) 0.36m

(b) 0.12m

(c) 0.18m

(d) 0.72m

Ans. (b)

21. The heat generated in a circuit is dependent upon the resistance, current and time for which the current is flown. If the error in measuring. The above are 1%, 2% and 1% respectively. The maximum error in measuring the heat is

(a) 8%

(b) 6%

(c) 18%

(d) 12%

Ans. (b)

22. A particle having charge 100 times that of an electron is revolving in a circular path of radius 0.8 m with one rotation per second. The magnetic field produced at the centre will be

(a) 10^-17 µ₀

(b) 10^-11 µ₀

(c) 10^-7 µ₀

(d) 10^-3 µ₀

Ans. (a)

23. The energy of an X-ray photon is 2 keV, then its frequency will be:

(a) 3.2 x l0^-6 per sec

(b) 5×10¹⁷per sec

(c) 2 x 10¹⁷ per sec

(d) 2 x l0¹⁸ per sec

Ans. (b)

24. A refracting angle of a prism is A and the refractive index of the prism is cot (A/2) Then, angle of minimum deviation is:

(a) 180° – 2A

(b) 90° – A

(c) 180° + 2A

(d) 180° – 3A

Ans. (a)

25. If the critical angle for total internal reflection from medium to vacuum is 30°. The velocity in the medium will be:

(a) √3 x 10⁸ m/s

(b) 6 x 10⁸ m/s

(c) 1.5 x 10⁸ m/s

(d) 3 x 10⁸ m/s

Ans. (c)

26. The length of an astronomical telescope adjusted for parallel light is 100 cm. If the magnification of the telescope is 19. The focal length of two lenses, i.e., objective and eye piece are

(a) 76 cm and 4 cm

(b) 95 cm and 5 cm

(c) 85 cm and 15 cm

(d) 82 cm and 18 cm

Ans. (b)

27. Doubly ionised helium atoms and hydrogen ions are accelerated from rest through the same potential drop. The ratio of the final velocities of helium and the hydrogen ions are:

(a) 1/2

(b) 1/√2

(c)√2

(d) 2

Ans. (b)

28. In a transformer, the number of turns of primary coil and secondary coil are 5 and 4 respectively. If 220 V is applied on the primary coil, then the ratio of primary current to the secondary current will be

(a) 9:5

(b) 5:9

(c) 5:4

(d) 4:5

Ans. (d)

29. If the distance between parallel plates of a capacitor is halved and dielectric constant is doubled then the capacitance will

(a) Remain the same

(b) Increase 4 times

(c) Increase 2 times

(d) Decrease 2 times

Ans. (b)

30. In a nuclear fission, 0.1% mass is converted into energy. The energy released by the fission of 1 kg mass will be:

(a) 9 x 10¹⁹ J

(b) 9 x 10¹⁷ J

(c) 9 xl0¹⁶ J

(d) 9 xl0¹³ J

Ans. (d)

31. The energy of hydrogen atom in the nth orbit is E_n, then the energy in the nth orbit of single ionised helium atom is:

(a) E_n/2

(b) 2E_n

(c) 4E_n

(d) E_n/4

Ans. (c)

32. Force between two identical bar magnets whose centres r metre apart is 4.8 N when their axis are in the same line. If the separation is increased to 2 r metres, the force between them is reduced to

(a) 0.3N

(b) 0.6N

(c) 2.4N

(d) 1.2N

Ans. (a)

33. An air capacitor of capacity C = 10 µF is connected to a constant voltage battery of 12 V. Now, the space between the plates is filled with a liquid of dielectric constant 5. The additional charge that flows now from battery to the capacitor is

(a) 24 µC

(b) 480 µC

(c) 600 µC

(d) 120 µC

Ans. (b)

34. Pure silicon at 300 K has equal electrons n_e and holes h concentration of                  1.5 x 10¹⁶/m3. Doping by indium increases number of holes h to 4.5 x 10²²/m3 then n_e ‘doped in silicon will be:

(a) 3.0x 10^-19/m³

(b) 5×10⁹/m³

(c) 4.5×10²²/m³

(d) 1.5xl0¹⁶/m³

Ans. (b)

35. In an atom bomb the reaction which occurs is:

(a) Thermo nuclear

(b) Uncontrolled fission

(c) Controlled fission

(d) Fusion

Ans. (b)