Question 1 of 69

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

Protects the RFI filter from overloading

Controls the current in R2

Controls the pulse rate for triggering the TRIAC

Protects from overload to TRIAC

Question 1 of 69

Question 2 of 69

2. Which oscillator provides highly accurate stable frequency?

Hartley oscillator

Quartz crystal oscillator

Colpitts oscillator

R.C phase shift oscillator

Question 2 of 69

Question 3 of 69

3. 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_s

(t_ton)= t_r+ t_d+ t_s

(t_ton)=  t_r -  t_d

Question 3 of 69

Question 4 of 69

4. How many characters are in hexadecimal number system?

12

6

8

16

Question 4 of 69

Question 5 of 69

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

Current control device

Voltage control device

Positive feedback device

Low input impedance device

Question 5 of 69

Question 6 of 69

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

By adding resistance to trigger level circuit

By adding resistance to CRO probe

By increasing volts/cm attenuator switch position

By increasing time/base attenuator switch position

Question 6 of 69

Question 7 of 69

7. What is the name of this amplifier?

Common emitter amplifier

Class B push pull amplifier

Class AB push pull amplifier

Common collector amplifier

Question 7 of 69

Question 8 of 69

8. What is the type of amplifier circuit?

Common base amplifier

Common collector amplifier

Class B push pull amplifier

Common emitter amplifier

Question 8 of 69

Question 9 of 69

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

Lower atomic number

Resistance is very low

Doping percentage is more

Valence electrons are two only

Question 9 of 69

Question 10 of 69

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

RL

Re

R1

R2

Question 10 of 69

Question 11 of 69

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

To phase shift the signal by 60°

To cancel noise distortion

To cancel second harmonic distortion

To phase shift the signal by 180°

Question 11 of 69

Question 12 of 69

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

Detector

Oscillator

Amplifier

Modulator

Question 12 of 69

Question 13 of 69

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

Base positive, emitter negative and collector negative

Base positive, emitter negative and collector positive

Base ground, emitter and collector positive

Base negative, emitter positive and collector negative

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Question 14 of 69

14. Which is a passive component?

Diode

Diac

Transistor

Capacitor

Question 14 of 69

Question 15 of 69

15. Which electronic circuit generates AC signal without input?

Oscillator circuit

Filter circuit

Amplifier circuit

Rectifier circuit

Question 15 of 69

Question 16 of 69

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

Storing the data inputs

Interface to binary system

Control the binary system

Segregating the input parameters

Question 16 of 69

Question 17 of 69

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

Minimum signal to noise ratio losses

Minimum distortion

Maximum voltage gain

Maximum current gain

Question 17 of 69

Question 18 of 69

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

Atomic bonding structure of atom

Atomic number of the atom of the material

Existence of valence electrons in atom

Atomic weight of the atom of the material

Question 18 of 69

Question 19 of 69

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

Positive feedback

Negative feedback

Rectifier with filter

Voltage multiplier

Question 19 of 69

Question 20 of 69

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

9.6 Volt

10.8 Volt

24 Volt

12 Volt

Question 20 of 69

Question 21 of 69

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

NOT gate

OR gate

AND gate

NOR gate

Question 21 of 69

Question 22 of 69

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

Monostable multivibrator

One shot multivibrator

Bistable multivibrator

Astable multivibrator

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Question 23 of 69

23. Which is an active component?

Resistor

Capacitor

Inductor

Transistor

Question 23 of 69

Question 24 of 69

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

NOR

NOT

AND

NAND

Question 24 of 69

Question 25 of 69

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

FET

DIAC

TRIAC

UJT

Question 25 of 69

Question 26 of 69

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

Function generator

Cathode ray oscilloscope

Voltage stabilizer

Radio frequency generator

Question 26 of 69

Question 27 of 69

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

As rectifier

As an oscillator

For amplification

For triggering

Question 27 of 69

Question 28 of 69

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

f_in = 1/2π√LC

f_in =1/(LC)√2π

f_in = 1/√2πL/C

f_r = 1/2π√LC

Question 28 of 69

Question 29 of 69

29. Which code indicates silicon semiconductor diode?

2N 3055

OA 79

IN 4007

BY 126

Question 29 of 69

Question 30 of 69

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

FET

IGBT

SCR

UJT

Question 30 of 69

Question 31 of 69

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

Acts as a closed switch

Acts as an amplifier

Acts as an oscillator

Acts as an open circuit

Question 31 of 69

Question 32 of 69

32. Which resistor is used to measure light intensity?

VDR

PTC

NTC

LDR

Question 32 of 69

Question 33 of 69

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

Switching

Amplification

Oscillation

Modulation

Question 33 of 69

Question 34 of 69

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

Two input OR gate

Two input NOR gate

Two input AND gate

Two input NAND gate

Question 34 of 69

Question 35 of 69

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

24700Ω - 27300Ω

22400Ω - 33600Ω

23750Ω - 26250Ω

25650Ω - 28350Ω

Question 35 of 69

Question 36 of 69

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

Capacitor input filter

RC filter

Series inductor filter

LC filter

Question 36 of 69

Question 37 of 69

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

PNP transistor

Field effect transistor

NPN transistor

Uni junction transistor

Question 37 of 69

Question 38 of 69

38. Why is negative feedback required in amplifier circuits?

To reduce the distortion

To increase the amplification factor

To increase the output voltage gain

To increase the output current gain

Question 38 of 69

Question 39 of 69

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

Loud speaker amplifier

Relaxation oscillator

Microphone input device

Broadcast transmitter

Question 39 of 69

Question 40 of 69

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

Arsenic

Boron

Antimony

Phosphorous

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Question 41 of 69

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

Collector region always operate with high voltage

Base collector region is reverse biased

It has to dissipate more heat

Output taken from collector terminal

Question 41 of 69

Question 42 of 69

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

Provides negative feedback

Provides positive feedback

Provides transistor biasing voltage

Provides DC supply

Question 42 of 69

Question 43 of 69

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

Holes in P material attracted to negative terminal

Electrons and holes are attracted towards supply terminals

Minority carriers in two materials are neutralized

Electron in N material is drifted to positive terminal

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Question 44 of 69

44. How does the depletion region behave?

As insulator

As semiconductor

As conductor

As resistor

Question 44 of 69

Question 45 of 69

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

Half the rated output

Rated output

Double the rated output

No output

Question 45 of 69

Question 46 of 69

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

Fourth quadrant

Third quadrant

Second quadrant

First quadrant

Question 46 of 69

Question 47 of 69

47. Which letter indicates the compound material cadmium sulphide?

'B'

'A'

'R'

'C'

Question 47 of 69

Question 48 of 69

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

Dividing decimal by 2

Multiplying decimal by 2

Divide decimal by 4

Multiplying decimal by 4

Question 48 of 69

Question 49 of 69

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

F_in = 2Fin

F_in = F

F_in = √2 F

F_in = ½ F

Question 49 of 69

Question 50 of 69

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

Output voltage will be reduced

Current through SCR OFF

SCR gets cut off

Gate loses control over conduction

Question 50 of 69

Question 51 of 69

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

0.8 V - 0.9 V

0.2 V - 0.3 V

0.4 V - 0.5 V

0.6 V - 0.7 V

Question 51 of 69

Question 52 of 69

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

Gates are forward biased with drain

Gates are forward biased

Gates are reverse biased with source

Gates are reverse biased

Question 52 of 69

Question 53 of 69

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

Amplifier

Speed control of motors

Multi vibrators

Oscillators

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?

Half of the rated output

One fourth of rated output

Full rated output

Zero voltage

Question 54 of 69

Question 55 of 69

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

Lightly doped and very larger

Heavily doped and very larger

Lightly doped and very thin

Heavily doped and very thin

Question 55 of 69

Question 56 of 69

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

Select input signal voltage

Select intensity of the beam

Select sweep speed

Select input voltage range

Question 56 of 69

Question 57 of 69

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

1.0 KHz

10.0 KHz

100.0 KHz

1000.0 KHz

Question 57 of 69

Question 58 of 69

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

No response

Improper tuning

Works with low volume

Humming sound

Question 58 of 69

Question 59 of 69

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

Reverse bias voltage becomes zero

No depletion region exists

Drain current becomes zero

Width of channel has maximum value

Question 59 of 69

Question 60 of 69

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

Regulator circuits

Rectification

Amplification

Triggering circuits

Question 60 of 69

Question 61 of 69

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

311.17 V

315.20 V

310.02 V

312.25 V

Question 61 of 69

Question 62 of 69

62. What is the type of amplifier?

Push Pull Amplifier

Emitter Follower Amplifier

Common Base Amplifier

Common Emitter Amplifier

Question 62 of 69

Question 63 of 69

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

Using N material gate instead of P material

Using P material instead of N material

Using N material instead of P material

Insulating layer instead of junction

Question 63 of 69

Question 64 of 69

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

Resistor

Transistor

Capacitor

Inductor

Question 64 of 69

Question 65 of 69

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

1.5

166

0.66

6600

Question 65 of 69

Question 66 of 69

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

To avoid false triggering

To maintain the motor speed constant

To increase the life of TRIAC

To increase the motor torque

Question 66 of 69

Question 67 of 69

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

DIAC

TRIAC

IGBT

SCR

Question 67 of 69

Question 68 of 69

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

High resistance range

High current carrying capacity

High thermal conductivity

High barrier voltage

Question 68 of 69

Question 69 of 69

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

Power factor

Resistance

Inductance

Frequency

Question 69 of 69