MCQ IN ELECTRONICS - 1

electronics engineering objective questions with answers
Electronics Questions and Answers
exam objective electronics engineering questions

1. Which one of the following is most suitable for measuring very small capacitances?
(a) Transformer ratio-arm bridge
(b) Schering bridge
(c) Wien’s bridge
(d) De-Saute bridge

Ans:-B

2. Which of the following are the requirements of a CRO (cathode ray oscilloscope) for display of high frequency signals (megahertz)?
1. Input capacitance should be low.
2. Cathode ray tube should be provided with post-acceleration.
3. Shrot persistence phosphors should be used in the screen.
4. Electromagnetic focussing and deflection system should be used
Select the correct answer using the codes given below:
Codes:
(a) l, 2 and 4
(b) l, 3 and 4
(c) 1, 2 and 3
(d) 2, 3 and 4

Ans:-D

3. The controlling torque and the electromagnetic damping of the flux meter are
(a) small and heavy respectively
(b) heavy and small respectively
(c) both heavy
(d) both small

Ans:-A

4. If an induction type energy meter runs fast, it can be slowed down by adjusting the
(a) lag
(b) light load
(c) position of braking magnet and making it move closer to the centre of the disc
(d) position of braking magnet and making it move away from the centre of the disc

Ans:-A

5. In the measurement of strain by Wheatstone bridge, the maximum sensitivity is obtained by a combination of
(a) an active and dummy strain gauges
(b) two active and two dummy strain gauges
(c) three active and one dummy strain gauges
(d) four active strain gauges

Ans:-C

6. In a digital voltmeter, ‘over-ranging’ implies switching
(a) OFF (1/2) digit
(b) ON (1/2) digit
(c) ON next 4 digits
(d) ON an indicator.

Ans:-B

7. Which of the following units are needed for designing a data acquisition system using 8085 microprocessor?
1. An AID converter
2. A DIA converter
3. A programmable peripheral device
4. A timer
Select the correct answer by using the codes given below:
Codes:
(a) l and 4
(b) 3 and 4
(c) l and 3
(d) 2 and 4

Ans:-C

Directions: The following questions consist 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 f the Assertion A and the Reason R are individually true and f 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 R are 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

8. Assertion (A): By superimposing the log magnitude versus phase angle plot of open-loop transfer function on Nichols chart, it is possible to determine the closed-loop frequency response of the system.
Reason (R): Nichols chart gives constant M and N loci in the gain-phase plane.

Ans:-A

9. Assertion (A): A communication satellite is a microwave link repeater.
Reason (R): A communication satellite receives the signal beamed up by an earth station. It amplifies this signal and retransmits it to ground station.

Ans:-B

10. Assertion (A): FM systems exhibit threshold.
Reason (R): Noise affects the instantaneous frequency in a non-linear fashion.

Ans:-B

11. The mean square value of the shot noise current
(a) Varies inversely as average current
(b) is independent of average current
(c) Varies as ?average current
(d) Varies directly as average current

Ans:- D

12. Consider the following features regarding satellite communication:
1. Height of Satellite
2: Downlink frequency
3. Gain of transmitting antenna
4. Gain of receiving antenna
The free space transmission loss depends on
(a) 1 and 3
(b) l and 2
(c) 2 and 3
(d) 3 and 4

Ans:-B

13. In a Mesh topology of communication network, if there are N stations, the total number of possible full duplex links is
(a) N—1
(b) N (N—1)
(c) N (N—1) / 2
(d) (N-1) / 2

Ans:-D

14. Values of VSWR measured by terminating the load end of a transmission line first with horn, then with a short and finally with a matched load, will be respectively
(a) 20, 1.9 and 1.01
(c) 1.9, 1.01 and 20
(b) 20, 1.01 and 1.9
(a) 1.9, 2O and 1.01

Ans:-D

15. In an 8085 microprocessor, the accumulator contents get altered by the instruction
(a) ANI 5C
(b) CMP C
(c) CPI 3A
(d) ORA A

Ans:- D

16. The maximum value of mutual Inductance of two inductively coupled coils with self inductance L1 = 49 mH and L 2 = 81 mH is
(a) 130 mH
(b) 63 mH
(c) 32 mH
(d) 3969 mH

Ans:-B

17 . The resonant frequency of a series RLC circuit is 1.5 MHz with the resonating capacitor set at l50 pF. If the bandwidth is 10 kHz, then the effective resistance of the circuit in Ohms would be approximately
(a) 29.5
(b) 14.75
(c) 9.4
(d) 4.7

Ans:-B

18. The system y (t) = tx (t) + 4 is
(a) Non-linear, time-varying and unstable
(b) Linear, time-varying and unstable
(c) Non-linear, time-invariant and unstable
(d) Non-linear, time-varying and stable

Ans:-A

19. A signal of bandwidth 4 kHz is recorded in a tape recorder at normal speed. If for transmission purposes, the recorder is replayed at 4 times the normal speed, then the transmission bandwidth will be
(a) 16 kHz
(b) 8 kHz
(c) 4 kHz
(d) 1 kHz

Ans:-A

20. In LED, light is emitted because
(a) Recombination of charge carriers takes place
(b) Diode gets heated up
(c) Light falling on the diode gets amplified
(d) Light gets reflected due to lens action

Ans:-A

21. The gain of a negative feedback amplifier is 40 dB. If the attenuation of the feedback path is 50 dB, then the gain of the amplifier without feedback is
(a) 78.92
(b) 146.32
(c) 215.51
(d) 317.23

Ans:-B

22. The following table provides a comparison of the performances of common base (CB), common emitter (CE) and common collector (CC) configurations of a transistor:
Parameter CB CE CC
1. Input impedance low medium high
2. Current gain high low high
3. Voltage gain >1 >1 <1
In this table, the performances of CB, CE and CC have been correctly indicated in respect of parameters
(a) 1, 2 and 3
(b) 1 and 2
(c) 2 and 3
(d) l and 3

Ans:-C

23. Which one of the following statements is NOT correct?
(a) If everything else is equal, then a 10 bit digital ramp ADC. will have a better resolution but a longer conversion time than an 8 bit ADC
(b) The conversion time for a successive approximation increase with the increase in input voltage
(c) A flash ADC does not contain a DAC
(d) VCO is the main component of a voltage to frequency ADC

Ans:-B

24. A full adder circuit may be constructed by using
(a) two 2-input AND gates and two 3-input. OR gates
(b) two half address and a 2-input AND gate
(c) two half address and a 2-input OR gate
(d) two 2-input AND gates and two 3-input XOR gates

Ans:-C

25. If (211) x = (152) g , then the value of base ‘x’ is
(a) 3
(b) 5
(c) 7
(d) 9

Ans:-C

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electronics engineering objective questions Free Online test
Solved exam objective electronics engineering questions
Question Bank in Electronics and Communication Engineering

1. Two coupled coils have L₁ = 0.6 H, L₂ = 0.6 H and coupling coefficient = 0.25 Coil 2 has 800 turns. If current I₁, in coil I is 6 sin 100t amps, then the voltage across coil 2 is

(a) 90 cos l00t volts

(b) 9 cos l00t volts

(c) 0.9 cos l00t volts

(d) 0.09 cos l00t volts

Ans:-A

2. Cascading two amplifiers will result in

(a) reduction in overall gain and increase in the overall bandwidth

(b) reduction in overall gain and reduction in the overall bandwidth

(c) increase in overall gain and increase in the. overall bandwidth

(d) increase in overall gain and reduction in the overall bandwidth

Ans:-D

3. A tank circuit of R.F. amplifier has a coil of Q factor of 100. It is tuned to a frequency of 1 MHz. The bandwidth of the circuit is

(a) 1 kHz

(b) 10 kHz

(c) 100 kHz

(d) 1000 kHz

Ans:-B

4. An amplifier with an initial open-loop gain of

400 is used as a negative feed back amplifier. The feedback factor is 0.05. If the gain of the amplifier changes by 10% due to temperature, then the closed-loop gain will change approximately by

(a) 0.05%

(b) 0.1%

(c) 0.5%

(d) l %

Ans:-C

5. The gain and input resistance of an amplifier in a boot-strap sweep circuit are respectively

(a) unity and zero

(b) infinity and infinity

(c) unity and infinity

(d) infinity and zero

Ans:-C

6. Consider the following processes in the fabrication of ICs:

1. Substrate

2. Oxide layer

3. Photo resist and photolithography

4. Etching

The correct sequence of these processes is

(a) 1,2,3,4

(b) 1,2,4,3

(c) 2,1,3,4

(d) 2,1,4,3

Ans:-A

7. A bulb is controlled by two switches A and B. The bulb glows only when either switch A or switch B is ON. Its Boolean expression is

(a) AB÷AB

(b) AB

(c) AB+AB

(d) AB÷AB

Ans:-D

8. Open-collector gates requires

(a) external output pull-up resistors

(b) external capacitor to ground

(c) a buffer at the output

(a) higher supply voltage

Ans:-A

9. In microprocessor based system, DMA facility is required to increase the speed of data transfer between

(a) microprocessor and I/O devices

(b) microprocessor and memory

(c) memory and I/O devices

(d) microprocessor, I/O devices and memory

Ans:-C

10. The bandwidth of a PCM system having two quantization levels is B. If the quantization level is increased to 8, the resultant bandwidth will be

(a) B

(b) 2B

(d) 3B

(a) 4B

Ans:-C

11. Consider the following statements:

The total number of modes entering an optical fiber depends on

1. core radius

2. wavelength of the optical source.

3. refractive index profile.

Of these statements:

(a) 1 and 2 are correct

(b) 2 and 3 are correct

(c) 1 and 3 are correct

(d) 1, 2 and 3 are correct

Ans:-C

12. A video monitor uses 600 lines per frame and 40 frames per second. Each scan line has a maximum of 1000 pixels. To display on the monitor, the highest frequency of the signal required is

(a) 24 MHz

(c) 6 MHz

(b) 12MHz

(d) 4MHz

Ans:-A

13. In a pulse radar system, the received echo energy is inversely proportional to (R is the range measured)

(a) (R) ^1/4

(b) R²

(c) R³

(d) R⁴

Ans:-A

14. The radio altimeter on board an aircraft is basically a

(a) Doppler radar

(b) MTI radar

(c) Continuous wave radar

(d) Frequency modulated CW radar

Ans:-D

15. The double integration of a unit step function will result

(a) A unit step function

(b) Ramp function

(c) Impulse

(d) Parabola

Ans:-D

16. Consider the following statements:

A circuit is said to be in resonance when the

1. Current delivered by the source is in phase with the source voltage.

2. Load current is in phase with the load voltage.

3. Power factor of the circuit is unity.

Of these statements:

(a) 1 and 3 are correct

(b) 1 and 2 are correct 4

(c) 2 and 3 are correct

(d) l, 2 and 3 are correct

Ans:-D

17. An antenna has radiation resistance of 30 ohm, equivalent resistance of 10 ohm for all other losses and directive gain of 4.0. The power gain of the antenna will be

(a) 4.0

(b) 3.0

(c) 2.0

(d) 1.33

Ans:-B

18. A dielectric material in an electric field gets polarized. If the polarization is non.-uniform, then there would be accumulation of

(a) bound charge only on the surface

(b) bound charge only within the material

(c) bound charge within the material as well as on the surface

(d) free charge on the surface of the dielectric

Ans:-C

19. Consider the following statements regarding negative feedback in a closed loop system:

1. It increases sensitivity.

2. It minimises the effect of disturbance.

3. There is a possibility of instability.

4. It improves the transient response.

Of these statements:

(a) 1, 3 and 4 are correct

(b) 1, 2 and 4 are correct

(c) 1, 2 and 3 are correct

(d) 2, 3 and 4 are correct

Ans:-D

20. Match List I with List II and select the correct answer using the codes given below in the lists:

List I (Loop transfer function)

A. K(s+1) / s2(s+10)

B. K / s (s + 2) (s² + 2s + 2)

C. K / s(s + 2) (s² + 2s + 5)

D.  K / s(s+4) (s² +4s+5)

List II

(Point(s) of root-locus plot)

1. One real breakaway point

2. Two real breakaway points

3. Three real breakaway points

4. One real and one pair of complex conjugate break-away points

Codes:

A B C D

(a) 1 2 4 3

(b) 1 2 3 4

(c) 2 1 4 3

(d) 2 1 3 4

Ans:-B

21. A system has a complex conjugate root pair of multiplicity two or more in its characteristic equation. The impulse response of the system will be

(a) A sinusoidal oscillation which decays exponentially, the system is therefore stable

(b) A sinusoidal oscillation with time multiplier, the system is therefore unstable

(c) A sinusoidal oscillation which rises exponentially with time; the system is therefore unstable

(d) A dc term and harmonic oscillation, the system therefore becomes limiting stable

Ans:-B

22. A lag compensation network

(a) Increases the gain of the original network without affecting the stability

(b) Does not affect stability on increased gain

(c) Reduces the steady-state error

(d) Reduces the speed of response

Ans:-C

23. A system G(s) is expressed in the state variable form as

X = JX + Bu

y = CX + Du

Consider the following statements with regard to the properties of Jordan canonical matrix J:

1. The diagonal element of J is poles of G(s).

2. All the elements below the principal diagonal are zeros.

3. All the elements above the principal diagonal are zeros.

Among these statements:

(a) 1 and.3 are correct

(b) 1 and 2 are correct

(c) 2 alone is correct

(d) 3 alone is correct

Ans:-B

24. A 0-300 V voltmeter has a guaranteed accuracy of 2 per cent of full-scale reading. If the voltage measured by this instrument is 180 V, then the limiting error will be

(a) Less than 2%

(b) Less than 3% but greater than 2%

(c) Less than 4% but greater than 3%

(d) 4%

Ans:-C

25. Which one of the following statements regarding Hay Bridge and Maxwell Bridge is correct?

(a) Hay bridge is same as Maxwell Bridge having resistor R₁ in parallel with C₁ in one arm

(b) Hay bridge has R₁ in series with C₁ with Maxwell bridge has R₁ in parallel with C₁

(c) Hay bridge has R₁in parallel with C₁and Maxwell bridge has R₁ in series with C₁

(d) Hay bridge and Maxwell bridge are similar but Hay bridge is used to measure unknown capacitance while Maxwell bridge is used to measure unknown inductance

Ans:-A

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mcq electronics paper
for IES – Free Practice paper
PSU Question Papers Electronics, Telecommunication
1. Match List I with List II and select the correct answer using the codes given below the lists
List I
(Device)
A. LED
B. Zener
C.Varactor
D. SCR
List II
(Biasing mode)
1. Forward bias
2. Reverse bias
Codes:
A B C D
(a) 1 1 2 2
(b) 1 2 1 2
(c) 1 2 2,1
(d) 2 2 1 1

Ans:-C

2. A medium bandwidth high-gain multistage transistor amplifier can be economically realised, if the coupling technique used between different stages is
(a) DC
(b) RC
(c) Transformer
(d) LC

Ans:-C

3. If negative feedback is introduced in an amplifier let in a shunt current configuration, then the input resistance will
(a) Increase
(b) Remain the same
(c) Decrease
(d) Increase, decrease or remain the same depending upon input

Ans:-C

4. A differentiator is rarely used in analog computers, because it
(a) Reduces the gain
(b) Decreases the output of the amplifier
(c) Amplifies noise, drift and other unwanted disturbances
(a) May cause oscillation

Ans:-C

5. In a time base generator, a constant current source (I) is used to drive a capacitance (C). The Output voltage across the capacitance as a function of time (t) is given by
(a) (1/C)t
(b) (C/I)t
(c) I Ct
(d) t / IC

Ans:-A

6. A particular FM radio station is having frequency deviation equal to 75 kHz Taking the maximum audio frequency as 15KHz, the transmission bandwidth is approximately equal to
(a) 90 kHz
(b) 180 kHz
(c) 270 kHz
(d) 360 kHz

Ans:-B

7. The noise margin of a digital IC is the
(a) Maximum frequency of extraneous voltage that does not cause a gate to change its state
(b) Maximum extraneous voltage that does not cause a gate to change its state
(c) Thermal noise voltage which causes a gate to change its state
(d) Minimum frequency of extraneous voltage that causes a gate to change its state

Ans:-A

8. If it is desired to have a 64 × 8 memory and f the memories available are of 16 x 4 size, then the number of memories required will be
(a) 8
(b) 6
(c) 4
(d) 2

Ans:-A

9. The most economical manner in which a high- speed decade counter can be realised is by using
(a) Synchronous binary counter
(b) Ripple binary counter
(c) Ring counter
(d) Johnson counters

Ans:-A

10. Which one of the following statements is true of SP register in 8086 microprocessor?
(a) It can be used for reading instruction from memory
(b) The result of arithmetic operation always goes to SP
(c) It can be used for reversing the string
(d) The control command first goes to SP

Ans:-A

11. Match List I with List II and select the correct answer using the codes given blow the lists
List I
A. Immediate addressing
B. Implied addressing
C. Register addressing
D. Direct addressing
List II
1. LDA 30 SC
2. MOV A,B
3. Lx 1H, 2050
4. RRC
Codes:
A B C D
(a) 3 2 1 4
(b) 3 4 2 1
(c) 3 2 4 1
(d) 2 3 1 4

Ans:-B

12. For a periodic function the spectral density and the autocorrelation functions form
(a) Fourier transforms pair
(b) Laplace transforms pair
(c) Hubert’s transform pair
(d) Z-transform pair

Ans:-A

13. Delay distortion in transmission lines exists when
(a) Different frequency components have different attenuation
(b) Alpha is a constant
(c) Beta is proportional to frequency ‘
(d) Beta is a constant

Ans:-C

14. The capacity of a channel is the
(a) Number of digits used in coding
(b) Bandwidth required for information
(c) Volume of information it can take
(d) Maximum rate of information transmision

Ans:-D

15. Match List I with List II and select the correct answer using the codes given below the lists:
List I
A. Collector modulation
B. Phase shift method
C. Balanced modulator
D. Amplitude limiter
List II
1. FM generation
2. DSB generation
3. AM generation
4. SSB generation
Codes:
A B C D
(a) 3 4 1 2
(b) 4 3 1 2
(c) 3 4 2 1
(d) 4 3 2 1

Ans:-C

16. The frequency deviation of an FM signal is in creased from 25 kHz to 50 kHz For the same sinusoidal modulating signal of 10 kHz, the improvement In the demodulated signal to noise power ratio will be
(a) 2.0
(b) 2.5
(c) 4.0
(d) 5.0

Ans:-A

17. With a real-time constraint, the transmission bandwidth needed for a digital signal with r symbols per second is equal to or greater than
(a) 1/r
(b) r/2
(c) r
(d) 2r

Ans:-D

18. The round-trip distance for a satellite relay may be as great as
(a) 5000 km
(b) 50000 km
(c) 100000 km
(d) 500000km

Ans:-B

19. Serration pulses in composite video waveform serve the purpose of
(a) Equalising the change in the integrator before the start of the vertical retrace
(b) Helping vertical synchronisation
(c) Helping horizontal synchronisation
(d) Preventing ghost picture

Ans:-D

20. In radar engineering, in order to make use of narrow beam antennas for achieving accuracy in target direction Indication, it is preferable to use frequencies in the range of
(a) Lower VHF
(b) Upper VHF
(c) Lower UHF
(d) Upper UHF

Ans:-A

21. In navigational systems, the polar coordinates give Information of
(a) Range and azimuthally angle
(b) Range and elevation angle
(c) Range, height and velocity of descent
(d) Range, azimuth and elevation

Ans:-D

22. The principle of bridge duplex working involves
(a) Potential balance
(b) Current balance
(c) Resistance balance
(d) Impedance balance

Ans:-B

23. If the field winding of an unloaded dc shunts motor gets opened while running, it will
(a) Stop
(b) Run with reduced speed
(c) Run with increased speed
(d) Rach

Ans:-A

24. A dc cumulatively compounded motor delivers rated load torque at rated speed, If the series field is short-circuited, then the armature current and speed will
(a) Both decrease
(b) Both increase
(c) Increase and decrease respectively
(d) Decrease and increase respectively

Ans:-B

25. A separately excited dc machine, having an armature resistance of 2 ohms was working on a 220 V supply and drawing 10 A armature current from the source when the supply voltage suddenly dropped to 200 V. Assuming that the field circa it source voltage remained unaffected, how will the armature current of the machine react to the change?
(a) It will initially rise to 11 A and then settle down to 10A
(b) It will fall momentarily to 9.09 A and then slowly attain 10 A
(c) It will reduce to zero first and then settle back to 10A
(d) It will remain unaffected by the change and continue to be 10 A

Ans:-B

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Semiconductor quiz electronics quiz
SEMICONDUCTOR UNIT QUIZ. Multiple Choice.
ELECTRONICS – Introduction to Semiconductor quiz
Free Online Quiz Objective MCQ Questions

1.  An example for insulator

a)      a.copper

b)      aluminium

c)      c.plastic

d)      none of these

Ans: c

2. An example for semiconductor

a)      copper

b)      aluminium

c)      mica

d)      germanium

Ans:d

3. Forbidden gap is

a)      gap between conduction band and valance band

b)      gap between covalant band and valance band

c)      gap between conduction band and energy band

d)      none of these

Ans:a

4. In conductor, Forbidden gap is

a)      large

b)      very large

c)      small

d)      overlapped

Ans:d

5. In insulator, Forbidden gap is

a)      large

b)      very large

c)      small

d)      overlapped

Ans:b

6. In semiconductor, Forbidden gap is

a)      small

b)      large

c)      zero

d)      none of these

Ans:a

7. A pure semiconductor is

a)      carbon

b)      extrinsic semiconductor

c)      zero semiconductor

d)      intrinsic semiconductor

Ans:d

8.After the valley point UJT acts as

a.transister

b.amplifier

c.contoller

d.forward PN Diode

Ans:d

9.UJT used in

a.pulse generator

b. electric circuit

c.either (a)&(b)

d.none of these

Ans:a

10.Diac is used as

a.triggering device

b. pulse generator

c. amplifier

d.contoller

Ans:a

11.Triac is

a.Two transister device

b.two diodes device

c.two diacs device

d.two SCR device

Ans:d

12.When Gate current is equal to zero,SCR acts as

a.Diode

b.transister

c.PNPN Diode

d.none of these

Ans:c

13..Triac has

a.one terminal

b.two terminal

c.three terminal

d.four terminal

Ans:c

14.Terminals of SCR

a.gate,emitter

b.gate,base.collector

c.anode,cathode,gate

d.none of these

Ans:c

15. A term ‘holding current’ used in

a.Diode

b.transister

c.PNPN Diode

d.SCR

Ans:d

16. A term ‘Zener breakdown voltage’ used in

a.Zener Diode

b.transister

c.PNPN Diode

d.SCR

Ans:a

17.A term ‘intrinsic standoff ratio’ used in

a.Diode

b.UJT

c.PNPN Diode

d.SCR

Ans:b

18. A term ‘latching current’ used in

a.Diode

b.transister

c.PNPN Diode

d.SCR

Ans:d

19.Which one is used as triggering device

a.Diode

b.UJT

c.PNPN Diode

d.none of these

Ans:b

20.SCR is used as

a.pulse generator

b. amplifier

c.contoller

d.none of these

Ans:c

21. Majority carriers of P type material

(a)        Electrons

(b)        Holes

(c)        Protons

(d)   None of these

Ans:b

22. Minority carriers of N type material

(a)        Electrons

(b)        Holes

(c)        Protons

(d)    None of these

Ans:b

23. Minority  carriers of P type material

(a)        Electrons

(b)        Holes

(c)        Protons

(d)      None of these

Ans:a

24. Terminals of diode

a.gate,emitter

b.gate,base.collector

c.anode,cathode,

d.none of these

Ans:c

25. Terminals of transistor

a.gate,emitter

b.gate,base.collector

c.anode,cathode,gate

d.base,emitter,collector

Ans:d

26.At room temperature, extrinsic semiconductor is

a)conductor

b)poor conductor

c)partially conductor

d)none of these

Ans:b

27.Which one is trivalent impurity

a)boron

b)antimony

c)silicon

d)none of these

Ans:a

28.Which one is pentavalent impurity

a)boron

b)antimony

c)silicon

d)none of these

Ans:b

29.Resistance of an ideal diode, resistance  during reverse biasing

(a)        Zero

(b)        Unity

(c)        Maximum

(d)        infinite

Ans:d

30. In CB Configuration of transistor, the output impedance is

(a)        High

(b)        medium

(c)        Low

(d)        none of these

Ans:a

31. In CB Configuration of transistor, voltage gain is

(a)        High

(b)        medium

(c)        Low

(d)        none of these

Ans:a

32. In CB Configuration of transistor, current gain is

(a)        High

(b)        medium

(c)        Low

(d)        almost one

Ans:d

33. In CE Configuration of transistor, the input impedance is

(a)        High

(b)        medium

(c)        Low

(d)        none of these

Ans:b

34. In CE Configuration of transistor, the output impedance is

(a)        High

(b)        medium

(c)        Low

(d)        none of these

Ans:b

35. In CC Configuration of transistor, the output impedance is

(a)        High

(b)        medium

(c)        Low

(d)        none of these

Ans:c

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

electronics Solved Questions for Diploma engineers Job exams
Supervisor Trainees model paper
Model mcq peper for jobs for Diploma Engineer

1. An ideal diode resistance has———resistance during forward biasing

(a)        Zero

(b)        Unity

(c)        Maximum

(d)       Minimum

Ans:a

2. Transistor is used as

(a)        Switch

(b)        Amplifier

(c)        Both (a) & (b)

(d)       None of these

Ans:c

3. Majority carriers of N type material

(a)        Electrons

(b)        Holes

(c)        Protons

(d)       None of these

Ans:a

4. Which one is semiconductor

(a)        Copper

(b)        Mica

(c)        Carbon

(d)       Silicon

Ans:d

5. Transistor is ———–Device

(a)        Bipolar

(b)        Unipolar

(c)        Constant current

(d)       Constant voltage

Ans:a

6. Diode is used as

(a)        Regulator

(b)        Inverter

(c)        Current Regulator

(d)       Rectifier

Ans:d

7. Zener diode acts as

(a)        Rectifier

(b)        Regulator

(c)        Inverter

(d)       None of these

Ans:b

8. Diode is ———–Device

(a)        Bipolar

(b)        Unipolar

(c)        Constant current

(d)       Constant voltage

Ans:b

9. Which one is intrinsic semiconductor

(a)        Copper

(b)        Mica

(c)        Carbon

(d)       Silicon

Ans:d

10. Which one is conductor

(a)        Copper

(b)        Mica

(c)        Carbon

(d)       Silicon

Ans:a

11. Which one is insulator

(a)        Copper

(b)        Mica

(c)        Carbon

(d)       Silicon

Ans:b

12. Ripple factor for half wave rectifier

(a)        1.11

(b)        1.21

(c)        1.5

(d)       0.48

Ans:b

13. Ripple factor for full wave rectifier

(a)        1.11

(b)        1.21

(c)        1.5

(d)       0.48

Ans:d

14. Ripple factor for bridge wave rectifier

(a)        1.11

(b)        1.21

(c)        1.5

(d)       0.48

Ans:d

15. BJT is ———–Device

(a)        Bipolar

(b)        Unipolar

(c)        Constant current

(d)       Constant voltage

Ans:a

16. SCR is

(a)        un controlled device

(b)        Regulator

(c)        controlled device

(d)       None of these

Ans:c

17. In CB Configuration of transistor, the input impedance is

(a)        High

(b)        medium

(c)        Low

(d)       none of these

Ans:c

18. Diac is

(a)        Unidirectional device

(b)        Bidirectional device

(c)        Constant device

(d)      None of these

Ans:b

19. Other name of SCR

(a)        Transistor

(b)        Diode

(c)        Thyristor

(d)       Resistor

Ans:c

20. UJT terminals are

(a)        Base 1,Base 2,Emitter

(b)        Base 1, collector,Emitter

(c)        Base 1,Base 2,Collector

(d)       None of these

Ans:a

21.A term intrinsic standoff ratio used in

(a)        diode

(b)       transistor

(c)        UJT

(d)      None of these

Ans:c

22.Which one works on negative resistance region

(a)        diode

(b)       transistor

(c)        UJT

(d)       None of these

Ans:c

23.SCR maybe considered as

(a)        two diode model

(b)       transistor model

(c)        two transistor model

(d)       None of these

Ans:c

24. Semiconductor is

1. conductor
2. insulator
3. either conductor or insulator
4. none of these

Ans:c

25. An example for conductor

1. copper
2. mica
3. plastic
4. carbon

Ans:a

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

COMPUTERS IN BIOMEDICAL INSTRUMENTATION
BIO-MEDICAL INSTRUMENTATION COMPUTER AIDED
application of computers in medicine
Bio Instrumentation – computer science

1. The way that computers manipulate data into information is called
   a) Programming
   b) Processing
   c) Storing
   d) Organizing                                                                                                            Ans : (b)

1. Computers use the ____________ language to process data.

a)    Processing

b)    Kilobyte

c)    Binary

d)    Representational                                                                                               Ans : (c)

3. ___________ is the starting point of health care.

a) Data collection

b) Decision making

c) Analyzing

d) Therapy                                                                                                                 Ans : (a)

4. ____________ is a set of computer programs used on a computer to help perform tasks.
a) An instruction
b) Software
c) Memory
d) A processor                                                                                                            Ans : (b)

5. Alpha numeric data includes results of

a) CT

b) Ultra sound

c) MRI

d) Lab                                                                                                                         Ans (d)

6. Image data will store images in digitized form on

a) Optical disks

b) Magnetic disks

c) Lens

d) LAN                                                                                                                        Ans : (a)

7. S1: In open loop control problem requires human intervention.

S2: In closed loop control processor instruct the control to do direct therapeutic intervention on the patient.

a)    Both S1 and S2 are false

b)    S1 is true and S2 is false

c)    Both S1 and S2 are true

d)    S1 is false and S2 is true                                                                                 Ans : (c)

8. A computer in which the quantities are processed and represented with out use of ________ is called an analogue computer.

a) Software

b) Hard ware

c) Programme

d) Language                                                                                                                         Ans: (d)

9. The process of reducing quantity of data is

a) Data handling capacity

b) Data reduction

c) Data processing

d) Programme                                                                                                          Ans: (b)

10. The _____________ is widely used to do signal processing of bio signals from the recorders.

a) CPU

b) Memory

c) ALU

d) Micro controller                                                                                                    Ans  d)

11. ___________ accepts data from outside.

a) Input

b) Output

c) Memory unit

d) Control unit                                                                                                          Ans: (a)

12. If the biomedical signal is electrical in nature a simple electrode is used to pass the signal   from body to

a) ADC

b) DAC

c) Signal conversion system

d) Sample and hold circuit                                                                                     Ans: (c)

13. Amplification is necessary to bring the amplitude of the signal into the range of

a) ADC

b) DAC

c) Signal conversion system

d) Sample and hold circuit                                                                                     Ans: (a)

14. ADC holds the analog signal at _________ value during conversion process.

a) The twice

b) A constant

c) Half the

d) Square the                                                                                                            Ans : (b)

15. _____________ is defined as the smallest input digital code for which a unique analog output level is produced.

a) Gain

b) Resolution

c) Accuracy

d) Sampling rate                                                                                                      Ans: (b)

16. In ADC the time required to complete one sample determines the

a) Maximum conversion time

b) Sampling rate

c) Settling time

d) Minimum sampling time                                                                                                Ans : (d)

17. The dynamic properties of sample and hold circuit are important in the overall performance of

a) ADC

b) DAC

c) Signal conversion system

d) Sample and hold circuit                                                                                     Ans: (a)

18. A variation of the counter ADC is

a) Dual slope

b) Filter

c) Tracking

d) Successive approximation                                                                                Ans : (c)

19. The transfer function of digital filter is defined as z transform of

a) Output sequence/ input sequence

b) Output sequence+ input sequence

c) Output sequence* input sequence

d) Output sequence- input sequence                                                                  Ans: (a)

20. ___________ is dependent only on round off error.

a) Gain

b) Resolution

c) Accuracy

d) Response                                                                                                                         Ans : (c)

21. The z transform is important in digital filtering because it describes

a) Maximum conversion time

b) Sampling process

c) Settling time

d) Sampling rate                                                                                                      Ans : (b)

22. In non recursive filters the transfer function contains

S1: Finite number of elements

S2: It is quadratic form

a)    Both S1 and S2 are false

b)    S1 is true and S2 is false

c)    Both S1 and S2 are true

d)    S1 is false and S2 is true                                                                                 Ans : (b)

23. The value of z for which the transfer function goes to _________ is called poles.

a) Zero

b) Unity

c) Infinity

d) Peak                                                                                                                      Ans : (c)

24. A __________ seeks to minimize the number of coded bits stored by reducing the redundancy present in the original signal.

a) Data reduction algorithm

b) Digital filtering

c) Time domain technique

d) Frequency domain technique                                                                          Ans : (a)

25. The original motivation of turning point algorithm was to reduce the_________ of an

ECG signal.

a) Gain

b) Response

c) Sampling rate

d) Sampling frequency                                                                                           Ans : (d)

26. Using turning point algorithm, the sampling frequency of ECG is reduced from

a) 200 to 100 samples/sec

b) 100 to 50 samples/sec

c) 250 to 100 samples/sec

d) 150 to 50 samples/sec                                                                                        Ans : (a)

27. The TP algorithm is simple and fast, producing a fixed reduction ratio of

a) 1:2

b) 3:1

c) 2:1

d) 1:3                                                                                                                          Ans : (c)

28. The originally developed algorithm to preprocess ECG’s for rhythm analysis is

a) TP

b) AZTEC

c) Data reduction

d) Data reconstruction                                                                                            Ans : (b)

29. _____________ algorithm is a hybrid of TP and AZTEC algorithms.

a) CORTES

b) FAN

c) Static Huffman coding

d) Adaptive coding                                                                                                   Ans : (a)

30. Expansion of CORTES

a) Cooperate Reduction Time Enlarging System

b) Coordinate Reduction Time Enlarging System

c) Cooperate Reduction Time Encoding System

d) Coordinate Reduction Time Encoding System                                             Ans : (d)

31. FA algorithm

S1: Draws lines between pairs of starting and ending points

S2: All intermediate samples are within some specified error tolerance

a) Both S1 and S2 are false

b) S1 is true and S2 is false

c) Both S1 and S2 are true

d) S1 is false and S2 is true                                                                                   Ans : (c)

32. The reduction ratio of Huffman coding depends on the distribution of

a) Source symbols

b) Binary code

c) Probability of occurrence

d) Variable length                                                                                                    Ans : (a)

33. An example of adaptive scheme is

a) Huffman coding

b) FAN algorithm

c) CORTES algorithm

d) LZW algorithm                                                                                                     Ans : (d)

34. _________ requires a translation table, where each source symbol is mapped into a unique code word.

a) Adaptive coding

b) Huffman coding

c) FAN algorithm

d) LZW algorithm                                                                                                     Ans : (b)

35. In _________ algorithm the dynamically derived translation table is sensitive to the variation in local statistical information.

a) Adaptive coding

b) Huffman coding

c) FAN algorithm

d) LZW algorithm                                                                                                     Ans : (a)

36. Huffman coding assigns variable length code words to a given quantized data sequence according to their

a) Time of occurrence

b) Amplitude of occurrence

c) Frequency of occurrence

d)  Discrète amplitude                                                                                             Ans : (c)

37. Bio medical signals are often corrupted by

a) Noise

b) Electrodes used

c) Amplifiers used

d) Power                                                                                                                    Ans : (a)

38. The digital computer algorithm for Fourier analysis is called as

a) Fourier Transform

b) Fast Fourier Transform

c) Inverse Fourier Transform

d) Inverse Fast Fourier Transform                                                                        Ans : (b)

39. The angular sampling frequency is given by ?_s =

a) 2?T

b) 2?-T

c) 2?+T

d) 2?/T                                                                                                                        Ans : (d)

40. For discrete signals the Fourier transform is continuous and repeats at intervals of

a) Positive frequencies

b) Negative frequencies

c) Sampling frequencies

d) Alternate positive and negative frequencies                                                  Ans : (c)

41. DFT is the name given to the calculation of the fourier series coefficients for a

a) Discrete periodic signal

b) Discrete aperiodic signal

c) Continuous periodic signal

d) Continuous aperiodic signal                                                                             Ans : (a)

42. In DFT

S1: The first spectral line gives amplitude of the DC component in the signal

S2: The second line corresponds to frequency.

a) Both S1 and S2 are false

b) S1 is true and S2 is false

c) Both S1 and S2 are true

d) S1 is false and S2 is true                                                                                   Ans : (c)

43. To increase ___________ we must divide the DFT into successively smaller DFTs.

a) Frequency

b) Computation efficiency

c) Sampling rate

d) Computation time                                                                                               Ans : (b)

44. Algorithm in which the decomposition is based on splitting sequence into smaller sequences are called

a) Inverse decimation in time

b) Inverse decimation in frequency

c) Decimation in time

d) Decimation in frequency                                                                                   Ans : (d)

45. Time domain convolution is often expressed in a short hand notation using a

a) *

b) +

c) –

d) **                                                                                                                             Ans : (a)

46. Parseval’s theorem expresses the conservation of __________ principle between the time and frequency domain.

a) Energy

b) Power

c) Frequency

d) Time                                                                                                                       Ans : (a)

47. Computer interpretation of __________ uses algorithm to determine whether a patient is normal or abnormal.

a) 8 lead ECG

b) 3 lead ECG

c) 12 lead ECG

d) 21 lead ECG                                                                                                         Ans : (c)

48. The interpretation program running in the mainframe computer consisted of several hundred thousand lines of __________ code.

a) C

b) C++

c) C#

d) FORTRAN                                                                                                            Ans : (d)

49. How many amplifiers does the modern micro processor based interpretive machines include?

a) 8

b) 12

c) 3

d) 4                                                                                                                             Ans : (a)

50. The modern ECG amplifiers have a sampling rate of

a) 100 sps

b) 500 sps

c) 250 sps

d) 300 sps                                                                                                                  Ans : (b)

51. The first step in ECG waveform recognition is to identify all the beats using a ___________ detection algorithm.

a) R wave

b) P wave

c) QRS wave

d) S wave                                                                                                                  Ans : (c)

52. S1: ECG interpretation is a frequency of interpretation process

S2: ECG interpretation is a waveform recognition process

a) Both S1 and S2 are false

b) S1 is true and S2 is false

c) Both S1 and S2 are true

d) S1 is false and S2 is true                                                                                   Ans : (d)

53. The R wave duration is

a) 71 ms

b) 70 ms

c) 80 ms

d) 1.14 ms                                                                                                                 Ans : (a)

54. _________ approach is based on a set of rules that operate on the measurement matrix derived from ECG.

a) Pattern recognition

b) Expert system

c) Decision logic

d) IF-THEN statement                                                                                             Ans : (c)

55. Which segment represents the period of ECG just after depolarization.

a) PQ

b) RS

c) QS

d) ST                                                                                                                           Ans : (d)

56. Which device is used for determining the potential cardiac problem of an ambulatory patient?

a) ECG

b) VCG

c) Holter recorder

d) PCG                                                                                                                       Ans : (c)

57. S1: Holter monitoring is same as intensive care monitoring.

S2: Holter monitoring has a monitoring device.

a) Both S1 and S2 are false

b) S1 is true and S2 is false

c) Both S1 and S2 are true

d) S1 is false and S2 is true                                                                                   Ans : (b)

58. Changes in the ST segment of ECG indicates that there is a deficiency in

a) Blood supply to heart muscles

b) Blood supply to lungs

c) Oxygen supply to lungs

d) Blood supply to veins                                                                                         Ans : (a)

59. The R wave amplitude is

a) 1.04 mV

b) 1.24 mV

c) 1.14 mV

d) 1.01 mV                                                                                                                 Ans : (c)

60. The iso electric line is located on the ECG between P and Q wave for a ______ milli second interval of near zero slope.

a) 35

b) 25

c) 20

d) 30                                                                                                                           Ans : (d)

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

sample test papers electronics
Electronics & Communication. Sample Test Paper
sample papers for electronics & Instrumentation graduates
sample question papers in electronics engg for PSU Jobs
sample previous year paper for Electronics Engineers

1. The difference between the number of atoms in a unit cell of a bcc crystal and an fcc crystal is
(a) 1
(b) 2
(c) 4
(d) 6

2. If a small amount of Cu is added to a Ni conductor, then the
(a) resistiviy of Ni will decrease at all temperatures because Cu is a better conductor than Ni
(b) residual resistivity of Ni at low temperatures will increase as Cu atoms act as defect centres
(c) resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects
(d) resistivity of Ni remains unaltered as Cu atoms give the same number of free electrons as Ni atoms

3. For the n-type semiconductor with n = N_P and p = ni ²/N_D the hole concentration will fall below the intrinsic value because some of the holes
(a) dropback to acceptor impurity states
(b) drop to donor impurity states
(c) virtually leave the crystal
(d) recombine with the electrons

4. Match List I (Magnetic materials) with List II (Dipole arrangement in external field) and select the correct answer using the codes given below the Lists:
List I List II

A. Paramagnetic 1. All dipoles are aligned in one preferred direction
B. Ferromagnetic 2. Half of the dipoles are aligned in opposite
direction and have equal magnitudes.
C. Antiferro-magnetic 3. Half of the dipoles (with equal magnitudes) are
aligned in opposite direction to other half having
equal but lower magnitudes.
D. Ferrimagnetic 4. All dipoles have equal magnitudes but are
randomly oriented.
Codes:
A B C D
(a) 4 3. 2 1
(b) 4 1 2 3
(c) 2 1 4 3
(d) 2 3 4 1

5. For an insulating material, dielectric strength and dielectric loss should be
respectively
(a) high and high
(b) low and high
(c) high and low
(d) low and low

6. Match List I (Optical devices) with List II (Electrical/optical characteristics) and select the correct answer using the codes given below Lists:
List I List II
A. LASER 1. Emits monochromatic light of low intensity
B. Solar Cell 2. Consumes electrical power due to the incident light
C. Photo diode 3. Delivers power to a load
D. LED 4. Emits monochromatic light of high intensity
Codes:
A B C D
(a) 4 3 1 2
(b) 3 4 2 1
(c) 4 3 2 1
(d) 3 4 1 2

7. Which one of the following is the best definition of a superconductor?
(a) It is a material showing perfect conductivity and Meissner effect below a critical temperature
(b) It is a conductor having zero resistance
(c) It is a perfect conductor with highest diamagnetic susceptibility
(d) It is a perfect conductor but becomes resistive when the current density through it exceeds a critical value

8. The ac resistance of a forward-biased p-n junction diode operating at a bias voltage ‘V’ and carrying current ‘I’ is
(a) zero
(b) a constant value independent of V and 1
(c) V/I
(d) delta V/ delta I

9. Match List I with List II and select the correct answer using the codes given
below the Lists:
List I List II
A. Drift current 1. Law of conservation of charge
B. Einstein’s equation 2. Electric field
C. Diffusion current 3. Thermal voltage
D. Continuity equation 4. Concentration gradient
Codes:
A B C D
(a) 2 1 4 3
(b) 4 3 2 1
(c) 4 1 2 3
(d) 2 3 4 1

10. Consider the following statements:
If an electric field is applied to an n-type semiconductor bar, the electrons and
holes move in opposite directions due to their opposite charges. The net current is
1. due to both electrons and holes with electrons as majority carriers.
2. the sum of electron and hole currents.
3, the difference between electron and hole current.
Which of these statements is/are correct?
(a) 1 alone
(b) 1 and 2
(c) 2 alone
(d) 3 alone

11. Consider the following circuit configurations:
1. Common emitter.
2. Common base.
3. Emitter follower
4. Emitter follower using Darlington pair.
The correct sequence in increasing order of the input resistances of these
configurations is
(a) 2, 1, 4, 3
(b) 1, 2, 4, 3
(c) 2,1,3,4
(d) 1,2,3,4

12. Match List I With List II and select the correct answer using the codes given
below the Lists:
List I List II
(Devices) (Property)
A. Silicon diode 1. High frequency applications
B. Germanium diode 2. Very low reverse bias saturation current
C. LED 3. Low forward bias voltage drop
D. PIN diode 4. Cut-off wavelength

Codes:
A B C D
(a) 1 3 4 2
(b) 2 4 3 1
(c) 1 4 3 2
(d) 2 3 4 1

13. The depletion layer across a p⁺ – n junction lies
(a) mostly in the p⁺ region
(b) mostly in the n – region
(c) equally in both the p⁺and n – regions
(d) entirely in the p⁺ region

14. Match List I (Biasing of the junctions) with List II (Functions) in respect of the BJT and select the correct answer using the codes given below the Lists:
List I List II
A. E-B junction forward bias and C-B 1. Very low gain amplifier
junction reverse bias
B. Both E-B and C-B junctions forward bias 2. Saturation condition
C. E-B junction reverse bias and C-B 3. High gain amplifier
junction forward bias
D. Both E-B and C-B junctions reverse bias 4. Cut-off condition
Codes:
A B C D
(a) 2 3 1 4
(b) 3 2 1 4
(c) 3 2 4 1
(d) 2 3 4 1

15. Match List I (Structures/characteristics) with List II (Reasons) in respect of JFET and select the correct answer, using the codes given below the Lists:
List I List II
A. n-channel JFET is better than p- 1. Reverse bias increases along the
channel JFET channel
B. Channel is wedge shaped 2. High electric field near the drain
and directed towards source
C. Channel is not completely closed at 3. Low leakage current at the gate
pinch-off terminal
D. Input impedance is high 4. Better frequency performance since Mu(n)>> Mu(p)

Code:
A B C D
(a) 4 1 2 3
(b) 4 2 1 3
(c) 3 1 2 4
(d) 3 2 1 4

16. Consider the following statements:
A four-layer PNPN device having two gate leads can be turned on by applying a
1. positive current pulse to the cathode gate.
2. positive current pulse to the anode gate.
3. negative current pulse to the anode gate.
4.’ negative current pulse to the cathode gate.
Which of these statements is/are correct?
(a) 1 alone
(b) 1 and 3
(c) 2 alone
(d) 2 and 4

17. Almost all resistors are made in a monolithic integrated circuit
(a) during the emitter diffusion
(b) while growing the epitaxial layer
(c) during the base diffusion
(di) during the collector diffusion

Directions:
The following items consist of two statements, one labelled the ‘Assertion A’ and the other, labelled the ‘Reason R’ You are to examine these two statements 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 R are 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

18. Assertion (A) : BaTiO₃ is a piezoelectric material and is used in a record player.
Reason (R) : In a piezoelectric transducer, stress induces polarization and an electric
field strains the material.

19. Assertion (A) : Hall crystal can be used as a multiplier of two signals.
Reason (R) : Hall voltage is proportional to the currents or voltages applied in
perpendicular directions across the Hall crystal.

20. Assertion (A) : The hybrid pi model of a transistor can be reduced to its h-parameter
model and vice-versa.
Reason (R) : Hybrid pi and h-parameter models are inter-related as both of them
describe the same transistor.

21. Assertion (A) : When light falls at the junction of a p-n photo diode, its P side becomespositive and N side becomes negative.
Reason (R) : When a photo diode is short-circuited, the current in the external circuit
flows from the P-side to the N-side.

22. Assertion (A) : Prescalers are used in digital counters to extend the frequency range.
Reason (R) : Prescalers are simple dividing circuits and as such do not have the
high frequency limitation of digital counters.

23. Assertion (A) : CRTs, used in TV receivers are of electrostatic deflection type and
those used in oscilloscopes are of magnetic deflection type.
Reason (R) : TV receivers need a large screen to view pictures, whereas accuracy
is the main consideration in oscilloscopes.

24. Assertion (A) : Alnico is commonly used for electromagnets.
Reason (R) : Alnico has low hysteresis loss.

25. Assertion (A) The solution of Poisson’s equation is the same as the solution of
Laplace’s equation.
Reason (R) : Laplace’s equation is a special case of Poisson’s equation for source-
free regions.

26. Assertion (A) : The fundamental loop of a linear directed graph contains four twigs
and two links corresponding to a given tree.
Reason (R) : Ina linear directed graph, a link forms a closed loop.

27. Assertion (A) : TI ‘zero-state’ response of a linear constant-parameter continuous-
time system can have components having the ‘natural frequencies of the system.

Reason (R) : The ‘forced frequency components in the response of the state for any
given input may not add up to the given zero initial value of the state.
The ‘natural frequency components may be needed to bridge the gap.

28. In a two-terminal network, the open-circuit voltage measured at the given terminals by an electronic voltmeter is 100 V. A short-circuit current measured at the same terminals by an ammeter of negligible resistance is 5 A. If a load resistor of 80 Ohm is connected at the same terminals, then the current in the load resistor will be
(a) 1A
(b) 1.25A
(c) 6A
(d) 6.25A

29 Consider the following statements:
1. Tellegen’s theorem is applicable to any lumped network.
2. The reciprocity theorem is applicable to linear bilateral networks.
3. Thevenin’s theorem is applicable to two-terminal linear active networks.
4. Norton’s theorem is applicable to two-terminal linear active networks.
Which of these statements are correct?
(a) l,2 and 3
(b) 1,2,3 and 4
(c) l,2 and 4
(d) 3 and 4

30. The network has 10 nodes and 17 branches. The number of different node pair voltages would be
(a) 7
(b )9
(c) 10
(d) 45

31. Consider the following statements:
A 3-phase balanced supply system is connected to a 3-phase unbalanced load.
Power supplied to t4is load can be measured using
1. two wattmeters.
2. One wattmeter.
3. three wattmeters.
Which of these statements is/are correct?
(a) 1 and 2
(b) 1 and 3
(c) 2 and 3
(d) 3 alone

32.A capacitor used for power factor correction in single-phase circuit decreases
(a) the power factor
(b) the line current
(c) both the line current and the power factor
(d) the line current and increases power factor

33. Consider the following statements:
If a network has an impedance of (i -j) as a specific frequency, the circuit
would consist of series
1. R and C
2. R and L
3. R,L and C
Which of these statements are correct?
(a) 1 and 2
(b) 1 and 3
(c) 1, 2 and 3
(d) 2 and 3

34. A network contains only independent current sources and resist6rs. If the values
of all resistors are doubled, the values of the node voltages
(a) will become half
(b) will remain unchanged
(c) will become double
(d) cannot be determined unless the circuit configuration and the values of the resistors
are known

35. Consider the following statements regarding the fundamental component f1, (t)
of an arbitrary periodic signal f(t):
It is possible for
1. the amplitude of f1 (t) to exceed the peak value of f(t).
2. f1 (t) to be identically zero for a non-zero f(t).
3. the effective value of f 1(t) to exceed the effective value of f(t).
Which of these statements is/are correct?
(a) 1 alone
(b) 1 and 2
(c) 2 and 3
(d) 1 and 3

36. Two coils have .elf-inductances of 0.09 H and 0.01 H and a mutual inductance of
0.015 H. The coefficient of coupling between the coils is
(a) 0.06
(b) 0.5
(c) 1.0
(d) 0.05

37. A transmission line having 50 Ohms impedance is terminated in a load of (40 +j
30)Ohms . The VS WR is
(a) j 0.033
(b) 0.8+j 0.6
(c) 1
(d)2

38. A vertical wire of 1 m length carries a current of 1 A at 10MHz. The total radiated
power is nearly
(a) 0.13W
(b) 0.88W
(c) 7.3W
(d) 73W

39. A cavity resonator can be represented by
(a) an LC circuit
(b) an LCR circuit
(c) a lossy inductor
(d) a lossy capacitor

40. The skip distance is
(a) same for each layer
(b) independent of frequency
(c) independent of the state of ionisation
(d) independent of transmitted power

Answers :

1	b
2	c
3	d
4	b
5	c
6	c
7	a
8	d
9	b
10	b
11	c
12	d
13	b
14	b
15	a
16	a
17	a
18	a
19	d
20	a
21	b
22	a
23	d
24	a
25	d
26	d
27	b
28	a
29	b
30	b
31	b
32	d
33	b
34	c
35	a
36	b
37	d
38	d
39	a
40	a

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Electronics & Communication Engineering ECE Sample Paper For SAIL MT Management Trainee technical
SAIL Graduate Engineer Jobs Solved paper
Electronics Eng Objective Quiz For Steel Authority India Exam

1. When BCC iron is heated, it changes to FCC iron resulting in
(a)contraction -in volume
(b) increase in volume
(c)no change in volume
(d) crack in the material

2. When copper is added to silver in small quantity so as to form an alloy, the resistivity of such an alloy is
(a) equal to the resistivity of copper
(b) equal to the resistivity of silver
(c) greater than the resistivity of copper
(d) in between the resistivity of silver and copper

3. Match List-I (Materials) with List-II (Applications of materials) and select the correct answer using codes given below the lists:
List-I List -II
(Materials) (Applications of materials)
A. Aluminum 1. Current carrying spring
B. Phosphor Bronze 2. Heating element
C. Carbon 3. Commutator brush
D. Ni chrome 4. Telephone chords and trolley wires
Codes:
A B C D
4 3 1 2
(b) 2 1 3 4
(c) 4 1 3 2
(d) 2 3 1 4

4. When a semiconductor bar is heated at one end, a voltage across the bar is developed. If the heated end is positive, the semiconductor is ?
(a) p-type
(b) n-type
(c) intrinsic
(d) highly degenerate

5. The conductivity of a semiconductor crystal due to any current carrier is NOT proportional to
(a.) mobility of the carrier
(b) effective density of states in the conduction band
(c) electronic charge
(d) surface states in the semiconductor

6. Amplification of ultrasonic waves is possible in a piezoelectric semiconductor under applied electric field. The basic phenomenon involved is known as
(a) Electrostriction
(b) Acousto-optic interaction
(c)Acoustic-electric interaction
(d) Stimulated Brillouin scattering

7. Piezoelectric quartz crystal resonators find application where
(a) signal amplification is required
(b) rectification of the signal is required
(c) signal frequency control is required
(d)modulation of signal is required

8. When certain percentage of silicon is added to iron, the resistivity of the iron increase by a factor of 5. If a transformer core is made out of this iron, as compared to the previous value when silicon was not added, the eddy current loss will be
(a) 77%
(b) 80%
(c) 83%
(d) 86%

9. Which of the following are the properties of ferromagnetic domains?
1. Permanent magnetisation
2. Atomic moments in individual domains are all aligned neither parallel to nor perpendicular to one another below Curie point temperature
3. Each domain is magnetically saturated
4. Above Curie temperature, domains disrupt
Select the correct answer using the codes given below :
Codes:
(a) 1 and 3
(b) 2 and 4
(c)1, 3 and 4
(d) 3 and 4

10. Match List-I (Insulators) with List-II (Resistivity) and select the correct answer
using codes given below the lists:
List-I List-II
(Insulators) (Resistivity)
A. Bakelite 1.10⁵ ohm-cm
B. Window glass 2.10⁹ ohm-cm
C. Pure silica 3.10¹³ ohm-cm
D; Mica 4. 10¹⁷ ohm-cm
Codes:
A B C D
(a) 4 3 1 2
(b) 1 2 4 3
(c) 4 2 1 3
(d) 1 3 4 2

11. Which of the following phenomena is most important when foodstuff is cooked in
a microwave oven?

(a) Resistive Joule heating
(b) Induction heating
(c)Dielectric heating
(d) Radiation heating

12. The frequency dependence of electronic polarizability of a dielectric is obtained by solving the equation:
mx=- ax- 2bx – 2E₀ cos wt. Consider the following statements:
In this equation,
1. a is the restoring force constant, the expression for which is obtained from Coulomb’s law
2. m is the combined mass of electrons and nucleus
3. b is the damping constant occurring due to emission of electromagnetic radiation
4 m x term arises due to altered velocity of electrons orbiting the nucleus in presence of field.
Which of the above statements are correct?
(a)1 and 2
(b) 1 and 3
(c)1,2 and 4
(d) 2,3 and 4

13. The correct sequence of the following in the increasing order of the values of
permittivity is
(a) Air, Vacuum, TaO₂ Glass
(b) Air, Vacuum, Glass, TaO₂
(c) Vacuum, Air, TaO₂ Glass
(d) Vacuum, Air, Glass, TaO₂

14. Match List-I (Polarization process) with List-Il (Approximate frequency) and select the correct answer using codes given below the lists:
List-I List-II
(Polarization process) (Approximate frequency)
A. Electronic polarization 1. 10² Hz
B. Ionic polarization 2. 10⁵ Hz
C. Orientation polarization 3. 10¹³ Hz
D. Space-charge polarization 4. 10¹⁵ Hz
Codes:
A B C D
a) 1 2 3 4
(b) 4 3 2 1
(c) 1 3 2 4
(d) 4 2 3 1

15. Which material among the following possesses excellent dielectric properties and good reliability for use in making capacitors?
(a)Silicon monoxide
(b) Silicon dioxide
(c) Tin oxide
(d) Chromium oxide
16. The most suitable material for making an LDR (Light dependent resistor) is a semiconductor material having
(a) Eg>> hv
(b) Eg > hv
(c) Eg=hV
(d) Eg<

17. Which one of the following is an essential components of electromechanical
relays?
(a)Graphite rod
(b) LED
(c)An electromagnet
(d) MOSFET

18. In a degenerate semiconductor, the majority carriers are controlled by
(a) Fermi-Dirac statistics
(b) Maxwell-Boltzmann statistics
(c) Bose-Einstein (B-E) statistics
(d) Pauli’s exclusion principle

19. Fermions are the particles, which obey
(a)Maxwell-Boltzmann’s statistics
(b)Bose-Einstein’s statistics
(c Heisenberg’s uncertainty principle
(d Pauli’s exclusion principle

20. Excess carriers are generated in a sample of N-type semiconductor by shining
light at one end. The current flow in the sample will be made up of
(a) diffusion flow of carriers
(b) drift flow of carriers
(c) both diffusion and drift flow of carriers
(d) neither diffusion nor drift flow of carriers

Answers :
1 : a
2: c
3: c
4: b
5: d
6: a
7: c
8: b
9: c
10: b
11 : b
12 : b
13: b
14: b
15 : d
16 : d
17 : c
18 : a
19 : d
20: a

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Free Online Quiz For Assistant Engineer in Doordarshan and AIR 2010
Free online objective Quiz containing Questions on
electrostatic ,Wires carrying charge,induced field and potential.Intensity of charged particles ,induced field in circular coil ,
electromagnet and electromagnetic field ,dipole moment

Units like coulomb,unit of force,gauss,potential energy,electrostatics
Physics knowledge quizz free

1. A particle is moving uniformly with an angular velocity ω on the circumference of a circle of radius r. The linear velocity will be given by
(a) rω
(c) r/ω
(b)2Πrω
(d) ω/r

Ans:a

2. Line spectrum is obtained from the?
(a) Sun
(b) Filament of the bulb
(c) Mercury lamp
(d) Burning coal

Ans:c

3. A moving charge produces:
(a) neither electric field nor magnetic field
(b) electro-static field only
(c) magnetic field only
(d) both magnetic and electro-static fields

Ans:c

4. α, β and γrays emitted from a radioactive source are passed through a 0.5 cm. thick aluminum sheet. The out going radiations will consist of:
(a) α, β and γray
(b) β and γray
(c) γray
(d) αrays
Ans:b

5. Light year is a unit of
(a) time
(b) distance
(c) velocity
(d) acceleration

Ans:b
6. It is easier to draw up wooden block along an inclined plane than bang it up vertically principally because:
(a) the friction is reduced
(b) only a part of the weight has to be overcome
(c) the mass becomes smaller
(d) g becomes smaller
Ans:b

7. If a piece of ice floating on the surface of water in a beaker melts completely, the level of water
(a) rises
(b) remains the same
(c) falls
(d) initially rises and then falls
Ans:b

8. A Kelvin thermometer and a Fahrenheit thermometer used to record temperature of melting metal, read the same. What will a celcius thermometer read at that temperature?
(a) 301.25°
(b) 273°
(c) 457°
(d) 760°
Ans:a

9. A hydrogen-filled balloon expands as it rises and may even burst after rising very high in the atmosphere. This happens because:
(a) the temperature increases with height
(b) the temperature decreases with height
(c) the atmospheric pressure increases with height
(d) the atmospheric pressure decreases with height

Ans:d

10. if two substances of equal volumes but of different densities are dropped from the same height simultaneously, then
(a) the body of lower density will reach the earth earlier
(b) both the bodies will reach the earth simultaneously
(c) The body of higher density will reach earlier
(d) It depends upon the place
Ans:b

11. When the bob of a pendulum is at the mean position (minimum displacement) of its motion, its total energy is:
(a) all potential
(b) zero
(c) all kinetic
(d) partly kinetic partly potential
Ans:c

12. A red and a green pencil are taken in a room illuminated with green light. In the room:
(a) both pencils will appear dark
(b) pencils will appear as red and green respectively
(c) red pencil.will appear dark and green pencil as green
(d) red pencil will appear red and green pencil dark

Ans:c
13. The consumption of electrical energy in the household is measured in terms of:
(a) Kilowatt hour
(b) Kilowatts
(c) Joules
(d) Kilo Joules

Ans:a

14. A magnet is placed in earth’s magnetic field with north pole of the magnet pointing north. At the neutral point:
(a) the earth’s magnetic field is zero
(b) the magnet’s magnetic field is zero
(c) the fields of the magnet and the earth are equal and in the same direction
(d) the fields of the magnet and the earth are equal and opposite

Ans:d

15. Sudden fall of a barometer reading indicates:
(a) storm
(b) dry weather
(c) fine weather
(d) cold weather

Ans:a

16. If a ball and a rectangular block of different metal when completely immersed in a liquid, have the same loss of weight, then
(a) ball and rectangular block have same density
(b) ball and rectangular block have Weight in air
(c) ball and rectangular block have same volume
(d) ball and rectangular block have immersed to the same depth

Ans:c

17. If the period of oscillation of a simple pendulum is 4 seconds and we want to convert it into a second pendulum, then we have to:
(a) make the length of the pendulum one fourth of the previous length
(b) double the length of the pendulum
(c) make the length of the pendulum half of the previous length
(d) double the mass of the bob

Ans:a

18. The escape velocity of a body from the earth depends upon:
(a) mass of the body
(b) radius of the earth as well as the value of g
(c) the radius of the earth only
(d) volume of the body

Ans:b

19. A cyclist taking a turn bends inside because:
(a) he feels pleasure in doing so
(b) he increases speed in doing so
(c) he obtains necessary Centripetal force
(d) he avoids accidents
Ans:c

20. If the surface of water in a lake is just going to freeze, then the temperature of water at the bottom is
(a) 0°C
(b) 4°C
(c) 3°C
(d) none of these
Ans:b

21. The tangent law is applicable only when:
(a) there are at least two magnetic fields
(b) there two uniform magnetic fields mutually perpendicular to each other
(c) one strong magnetic field and the other weak magnetic field
(d) in the present magnetic fields one should be horizontal component of the earth’s magnetic field
Ans:b

22. A moving coil galvanometer is converted into an ammeter by putting:
(a) a high resistance in parallel
(b) a low resistance in series
(c) a low resistance in parallel
(d) a high resistance in series
Ans:c

23. Lenz’s law is derived from the law of conservation of:
(a)momentum
(b) energy
(c)charge
(d) magnetism
Ans:b

24. On which one of the factors does the sensivity of a galvanometer depend?
(a) number of the turns of the coil
(b) the temperature of the room
(c) the current flowing in it
(d) the potential difference between the two ends.
Ans:a

25. The wavelength of X-rays is of the order of:
(a) 0.1 cm
(b) 10 ²cm
(c)10 ^-4cm
(d)10 10 ^-8cm
Ans:d

26. Lamps used for street lighting are connected in
(a) parallel
(b) series and parallel both
(c) series
(d) none of the above
Ans:a

27. A. C. can be measured with the help of:
(a) moving coil galvanometer
(b) hot wire ammeter
(c) tangent galvanometer
(d) galvanometer

Ans:b

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