Question 1 of 69

1. What is the function of R1 variable resistor in a TRIAC circuit?

Protects from overload to TRIAC

Controls the pulse rate for triggering the TRIAC

Protects the RFI filter from overloading

Controls the current in R2

Question 1 of 69

Question 2 of 69

2. What is the use of time-base control switch or knob in the CRO?

Select sweep speed

Select input voltage range

Select input signal voltage

Select intensity of the beam

Question 2 of 69

Question 3 of 69

3. What is the output voltage in the full wave rectifier circuit?

Half the rated output

Rated output

No output

Double the rated output

Question 3 of 69

Question 4 of 69

4. What is the difference in current control of MOSFET compared to JFETs?

Insulating layer instead of junction

Using P material instead of N material

Using N material gate instead of P material

Using N material instead of P material

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Question 5 of 69

5. What is the type of amplifier?

Push Pull Amplifier

Emitter Follower Amplifier

Common Base Amplifier

Common Emitter Amplifier

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Question 6 of 69

6. What is the name of this amplifier?

Common collector amplifier

Class AB push pull amplifier

Class B push pull amplifier

Common emitter amplifier

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Question 7 of 69

7. How can the input impedance of CRO be increased?

By adding resistance to trigger level circuit

By increasing volts/cm attenuator switch position

By adding resistance to CRO probe

By increasing time/base attenuator switch position

Question 7 of 69

Question 8 of 69

8. What is the total turn-on time (t_ton) while transistor makes a transition from V₂ to V₁?

(t_ton)= t_d + t_r

(t_ton)=  t_r -  t_d

(t_ton)= t_r+ t_d+ t_s

(t_ton)= t_r - t_s

Question 8 of 69

Question 9 of 69

9. What is the power gain of CE amplifier with a voltage gain of 66 and β (Beta) of the transistor is 100?

166

6600

0.66

1.5

Question 9 of 69

Question 10 of 69

10. How many characters are in hexadecimal number system?

8

12

6

16

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Question 11 of 69

11. What is the main application of a Field Effect Transistor (FET)?

Current control device

Low input impedance device

Voltage control device

Positive feedback device

Question 11 of 69

Question 12 of 69

12. What defect will occur in the radio if the pulsations are not removed from the input of the rectifier?

No response

Works with low volume

Improper tuning

Humming sound

Question 12 of 69

Question 13 of 69

13. What is the peak voltage of 220V RMS AC voltage?

312.25 V

315.20 V

310.02 V

311.17 V

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Question 14 of 69

14. What is the characteristic property of base material in a transistor?

Heavily doped and very larger

Lightly doped and very thin

Heavily doped and very thin

Lightly doped and very larger

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Question 15 of 69

15. How is the gate terminal of N-channel JFET biased?

Gates are forward biased

Gates are reverse biased

Gates are reverse biased with source

Gates are forward biased with drain

Question 15 of 69

Question 16 of 69

16. Which is a passive component?

Capacitor

Transistor

Diode

Diac

Question 16 of 69

Question 17 of 69

17. What is the reason for widened barrier in a reverse biased diode?

Minority carriers in two materials are neutralized

Electrons and holes are attracted towards supply terminals

Electron in N material is drifted to positive terminal

Holes in P material attracted to negative terminal

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Question 18 of 69

18. Which quantity can be measured by CRO (Cathode Ray Oscilloscope)?

Power factor

Frequency

Inductance

Resistance

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Question 19 of 69

19. Which electronic circuit produces signal waves or pulses without an input?

Detector

Modulator

Amplifier

Oscillator

Question 19 of 69

Question 20 of 69

20. What is the minimum and maximum value of a resistor with color bands: red, violet, orange, and gold?

22400Ω - 33600Ω

23750Ω - 26250Ω

25650Ω - 28350Ω

24700Ω - 27300Ω

Question 20 of 69

Question 21 of 69

21. What is the purpose of connecting L1 through C1 to the transistor base?

Provides positive feedback

Provides negative feedback

Provides transistor biasing voltage

Provides DC supply

Question 21 of 69

Question 22 of 69

22. How does the depletion region behave?

As insulator

As resistor

As conductor

As semiconductor

Question 22 of 69

Question 23 of 69

23. What is the main function of Uni Junction Transistor (UJT)?

Loud speaker amplifier

Microphone input device

Relaxation oscillator

Broadcast transmitter

Question 23 of 69

Question 24 of 69

24. Why is the collector region physically made larger than emitter region in a transistor?

Collector region always operate with high voltage

It has to dissipate more heat

Base collector region is reverse biased

Output taken from collector terminal

Question 24 of 69

Question 25 of 69

25. Why are most semiconductor devices made from silicon compared to germanium?

High thermal conductivity

High current carrying capacity

High barrier voltage

High resistance range

Question 25 of 69

Question 26 of 69

26. What is the formula to calculate the resonance frequency in an oscillator circuit?

f_in = 1/√2πL/C

f_in =1/(LC)√2π

f_r = 1/2π√LC

f_in = 1/2π√LC

Question 26 of 69

Question 27 of 69

27. Which filter circuit is capable of removing voltage spikes in the rectifier circuit?

Capacitor input filter

Series inductor filter

LC filter

RC filter

Question 27 of 69

Question 28 of 69

28. What is the output DC voltage in half wave rectifier, if the input AC voltage is 24 volt?

10.8 Volt

9.6 Volt

24 Volt

12 Volt

Question 28 of 69

Question 29 of 69

29. What is the reason for higher barrier voltage in silicon material?

Valence electrons are two only

Doping percentage is more

Resistance is very low

Lower atomic number

Question 29 of 69

Question 30 of 69

30. What is the name of this logic gate symbol? [Two input logic gate]

Two input NOR gate

Two input OR gate

Two input NAND gate

Two input AND gate

Question 30 of 69

Question 31 of 69

31. How can a decimal number be converted into binary number?

Multiplying decimal by 2

Multiplying decimal by 4

Dividing decimal by 2

Divide decimal by 4

Question 31 of 69

Question 32 of 69

32. What is the input ripple frequency (F_in) of full wave rectifier?

F_in = 2Fin

F_in = √2 F

F_in = ½ F

F_in = F

Question 32 of 69

Question 33 of 69

33. Which resistor is used to measure light intensity?

LDR

PTC

VDR

NTC

Question 33 of 69

Question 34 of 69

34. Which device has very high input impedance, low noise output, good linearity and low inter-electrode capacity?

NPN transistor

Uni junction transistor

PNP transistor

Field effect transistor

Question 34 of 69

Question 35 of 69

35. Why is negative feedback required in amplifier circuits?

To increase the amplification factor

To increase the output current gain

To reduce the distortion

To increase the output voltage gain

Question 35 of 69

Question 36 of 69

36. What is the main application of SCR (Silicon Controlled Rectifier)?

Speed control of motors

Oscillators

Amplifier

Multi vibrators

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Question 37 of 69

37. Which resistor determines the voltage gain in a common emitter amplifier?

R1

R2

Re

RL

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Question 38 of 69

38. Which doping material is used to make P-type semiconductor?

Arsenic

Phosphorous

Antimony

Boron

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Question 39 of 69

39. What is the purpose of using Binary Coded Decimal (BCD) system in digital circuits?

Interface to binary system

Segregating the input parameters

Storing the data inputs

Control the binary system

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Question 40 of 69

40. Which code indicates silicon semiconductor diode?

2N 3055

OA 79

BY 126

IN 4007

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Question 41 of 69

41. What is the effect if SCR is latched into conduction and gate current is removed in DC?

SCR gets cut off

Output voltage will be reduced

Gate loses control over conduction

Current through SCR OFF

Question 41 of 69

Question 42 of 69

42. Which logic gate's operation is represented by this truth table?

AND gate

OR gate

NOR gate

NOT gate

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Question 43 of 69

43. Which is an active component?

Capacitor

Resistor

Inductor

Transistor

Question 43 of 69

Question 44 of 69

44. Which letter indicates the compound material cadmium sulphide?

'C'

'R'

'B'

'A'

Question 44 of 69

Question 45 of 69

45. What is the type of amplifier circuit?

Common emitter amplifier

Class B push pull amplifier

Common collector amplifier

Common base amplifier

Question 45 of 69

Question 46 of 69

46. What is the effect of pinch-off voltage in JFET?

Width of channel has maximum value

No depletion region exists

Drain current becomes zero

Reverse bias voltage becomes zero

Question 46 of 69

Question 47 of 69

47. What is the minimum voltage required in the base-emitter junction to conduct a silicon transistor?

0.6 V - 0.7 V

0.8 V - 0.9 V

0.4 V - 0.5 V

0.2 V - 0.3 V

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Question 48 of 69

48. Which multivibrator produces a repetitive pulse wave form output?

Astable multivibrator

Bistable multivibrator

One shot multivibrator

Monostable multivibrator

Question 48 of 69

Question 49 of 69

49. Which oscillator provides highly accurate stable frequency?

R.C phase shift oscillator

Quartz crystal oscillator

Colpitts oscillator

Hartley oscillator

Question 49 of 69

Question 50 of 69

50. What determines whether a material is a conductor, semiconductor or insulator?

Existence of valence electrons in atom

Atomic number of the atom of the material

Atomic weight of the atom of the material

Atomic bonding structure of atom

Question 50 of 69

Question 51 of 69

51. Which instrument provides a visual representation of measured quantities?

Voltage stabilizer

Cathode ray oscilloscope

Function generator

Radio frequency generator

Question 51 of 69

Question 52 of 69

52. Which biasing is required for an NPN transistor to function as an amplifier?

Base negative, emitter positive and collector negative

Base positive, emitter negative and collector positive

Base ground, emitter and collector positive

Base positive, emitter negative and collector negative

Question 52 of 69

Question 53 of 69

53. Which logic gate's operation is represented by this truth table?

NAND

AND

NOT

NOR

Question 53 of 69

Question 54 of 69

54. What is the output voltage if the center tap of transformer is open circuited in a full wave rectifier circuit?

One fourth of rated output

Full rated output

Zero voltage

Half of the rated output

Question 54 of 69

Question 55 of 69

55. Which electronic circuit generates AC signal without input?

Rectifier circuit

Oscillator circuit

Filter circuit

Amplifier circuit

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Question 56 of 69

56. What is the main advantage of a class A amplifier?

Maximum voltage gain

Maximum current gain

Minimum distortion

Minimum signal to noise ratio losses

Question 56 of 69

Question 57 of 69

57. Why is a feedback network used in the oscillator?

To cancel noise distortion

To phase shift the signal by 60°

To phase shift the signal by 180°

To cancel second harmonic distortion

Question 57 of 69

Question 58 of 69

58. What is the main application of uni junction transistor?

Regulator circuits

Amplification

Triggering circuits

Rectification

Question 58 of 69

Question 59 of 69

59. Why is a snubber circuit used in the TRIAC motor control circuit?

To increase the motor torque

To avoid false triggering

To increase the life of TRIAC

To maintain the motor speed constant

Question 59 of 69

Question 60 of 69

60. Which quadrant operation of SCR delivers heavy current in reverse biasing?

First quadrant

Fourth quadrant

Third quadrant

Second quadrant

Question 60 of 69

Question 61 of 69

61. What is the frequency of the displayed signal on CRO screen covered by 5 divisions with a time base setting of 0.2 microseconds?

1000.0 KHz

100.0 KHz

1.0 KHz

10.0 KHz

Question 61 of 69

Question 62 of 69

62. What is the purpose of DIAC in power control circuits?

As an oscillator

As rectifier

For amplification

For triggering

Question 62 of 69

Question 63 of 69

63. Which type of control device is used in electronic fan regulator control circuits?

TRIAC

UJT

FET

DIAC

Question 63 of 69

Question 64 of 69

64. Which is the advanced version of power electronic component used in the output stage in drives?

FET

SCR

IGBT

UJT

Question 64 of 69

Question 65 of 69

65. What is the primary function of this transistor circuit?

Modulation

Amplification

Oscillation

Switching

Question 65 of 69

Question 66 of 69

66. Which device is made up of using the methods of point contact, grown, diffusion and alloy junctions?

Transistor

Capacitor

Resistor

Inductor

Question 66 of 69

Question 67 of 69

67. Which circuit is essential to maintain oscillations in an oscillator circuit?

Negative feedback

Positive feedback

Voltage multiplier

Rectifier with filter

Question 67 of 69

Question 68 of 69

68. What is the function of a transistor if emitter to base and collector to base are forward biased?

Acts as an open circuit

Acts as an oscillator

Acts as a closed switch

Acts as an amplifier

Question 68 of 69

Question 69 of 69

69. What is the name of this three-terminal electronic device symbol?

IGBT

TRIAC

SCR

DIAC

Question 69 of 69