HAL electronics and electrical

HAL Management Trainee Written test Pattern
Written test mode : On line Test
Written Test Type-Objective
Time limit : 2 1/2 Hours
No of Questions :160
Total Parts-3
Part-1
No of Questions-20 (General Awareness)
Part -2- 
No of questions-40 (English and Reasoning)

Part-3
No of Questions :100 (Concerned Discipline)


HAL electronics and electrical questions with answers

1. When length of a wire increases its resistance 

a. doubles b. half c. remains same

Ans: ( a )

2. When a 50 Hz ,6-pole Induction Motor runs at 975rpm,the rotor emf frequency is 

a. 12.5Hz b. 1.25Hz c. 4Hz

Ans: ( b )

3. When a 6 pole 50Hz Induction Motor runs at 1450 rpm , it’s working mode is

a. motoring b. braking c. generating

Ans: ( a )

4. Slips for Different modes of operation of Induction Motor are

answer: motoring -0<S<1,generating- S<0,braking - S>1

5. Damping ratio ( ξ ) is 0.75, natural frequency is 12 rad/s are given & asked to find peak time

6. In electrodynamo-meter type wattmeter 

a. pressure coil is made fixed

b. current coil is made fixed

c. both the coils are made fixed

Ans: ( a )

7. In flux meter control torque is produced by 

a. weights attached to it.

b. Springs

c. No control torque is there

Ans: ( c )

8. One question regarding hot wire instrument

9. In MI meters deflecting torque is proportional to 

a. square of the current

b. square of the voltage

Ans: ( a )

10. In 3-Φ system total power is given by 

a. √3V­LILcos Φ

b. 3V­LILcos Φ

c. V­LILcos Φ 

Ans: ( a )

11. From supply one 3-Φ step-down transformer is drawing 10 A, the secondary current will be minimum when the transformer is 

a. star-delta

b. delta-star

c. delta-delta

d. star-star

Ans: ( b )


12. Transformer rating is expressed in 

a. KVA

b. KVAR

c. KW

Ans: ( a )


13. Manganin is a 

a. Insulator

b. Semi-conductor

c. Alloy


14. Dual scope oscilloscope has 

a. two separate horizontal and two separate vertical plates

b. one horizontal and two separate vertical plates

c. two separate horizontal and one vertical plates

d. one horizontal and one vertical plates


15. Standard Cell voltage is measured by 

a. MI meter 

b. MC meter

c. Potentiometer


16. The input resistance of the CRO is of the order of 

a. tens of ohm

b. mega ohm

c. kilo ohm

d. fraction of an ohm

Ans: ( b )


17. Errors are introduced in Wheatstone bridge due to 

a. lead resistance

b. contact resistance

c. some thing is given

d. all of the above

18. HRC fuse and circuit-breaker combination is used CB operates for 

a. low over-load currents

b. high over-load currents

c. combination is never used

19. G(s) = K / s(s+5)(s+1) is given to find the value of K for stable operation

20. By increasing gain of the system root locus will 

a. moves away from poles

b. moves away from zeros

c. crosses imaginary axis

Ans: ( a )

21. When the load current is high while measuring power using wattmeter 

a. current coil is connected near load

b. pressure coil is connected near load

22. C = 0.01µF and L = 1 mH and current is 10 A and asked to find the voltage drop


23. Transmission line is terminated by R and no reflection is there , then the value of R is _________ 

Ans: 400 ohm

24. One question regarding shunt ohm-meter and seriea ohm-meter

25. Inverted V curves are drawn between ________ 

Ans: field current Vs power factor


26. Conductor size is based on ?
a) depeding upon the transmission line distance

Ans: might be 'a'

27. Which of the following transformers can be connecte in parallel

a) delta-delta, delta-star
b) delta-star , star-star
c) delta-delta , star-star
d) delta-star, star-delta

28. Compensating coil is connected in wat way in lpf wattmeter

Ans: around CC and in series with the PC

29. The input impedance is in the range of ____ in Digital Volt Meter

Ans: in Mega Ohm

30. The input and output impedance of an ideal opamp

31. Two resistances are connected in series and parallel manner..and the values of overall series and parallel connections is given and then asked to find out the two resistances.

32. Question on finding the power angle when the input to the generator is increased

33. Ferranti effect is obtained when?

Ans: when the sending voltage is less than receiving voltage

34. Which type of logic family used in

Ans: Emitter coupled Logic



35. When the temperature of the room increased then the energy of semiconductor…

36. Power diode is generally made from: - Silicon/Germanium/Both/None of these

37. Thermionic Emission of electron is due to………….

38. When the both junction of NPN diode is reverse biased, then the diode is in which mode: -

a) Active b) Cutoff c) Saturation d) inverted

39. Which transistor mode gives the inverted output: -

a) Common Emitter b) Common Base c) Common Collector d) None of these

40. Which coupling gives the higher gain in case of amplifier: -

a) Capacitor coupling b) Impedance coupling c) Transformer coupling

41. Which distortion is least objectionable in audio amplification: -

a) Phase b) Frequency c) Harmonic d) Intermediation

42 A narrowband amplifier has a band pass nearly…………of central frequency:-

a) 33.3% b) 10% c) 50%

43 Frequency of wein bridge oscillator

44. Phase shift oscillator consists: -

a) RL b) RC c) RLC

45. Crystal oscillator frequency is very stable due to:-

46. Multivibrater Produces: -

a) Sine wave b) Square wave c) Smooth wave d) sawtooth

47. Convert the 101101 Binary number into octal no: -

a) 65 b) 55 c) 51 d) 45

48. 10 in BCD: -

a) 10100 b) 1100 c) 010111 d) None of these

49. Which PNP device has a terminal for synchronizing purpose:-

a) SCS b) Triac c) Diac d) SUS

50. In 3-Phase full converter, the output during overlap is equal to……………..

51. Addition of indium in semiconductor crystal makes: -

a) PNP b) NPN

52. Free electron exists in which band: -

a) 1 b) 2 c) 3 d) Conduction band

53. Ripple factor of half wave rectifier: -

a) 1.21 b) 0.48 c) 0.5

54. The input and output impedance of an ideal opamp

55. Efficiency of half wave rectifier: -

56. Finding the power angel in power system

57. The motor used in fruit juicer

58. LVDT is used in finding th displacement

59 Cross magnetization will come with wat pf

60. The type of converter used in HVDC

61. The relationship b/w the airgap and current in light

62. Corrona loss is less in which type of shaped conductor?( the question is asked 2 times)

Ans: circular

63.The motor used in low speed applications?

64. If the accuracy of an instrument is 5% for 100A current ,accuracy for 50A current?

65 A question on time constant of a coil(R-L) circuit!

66. Effect of line commutated inductance in inverter

a) increase current ripple
b) reduces current ripple
c) increases output voltage
d) reduces output voltage

67. The type of bridge is used for Low Q applications

ans: maxwells bridge

68. A question on PSM and TSM in power system

69. The advantage of PI controller over P controller

70. The power gain is highest in wat amplifier

Ans : common emitter

71. Power of a converter with ac input supply and dc output current

a)1
b)0.98
c)0.95
d)0.92

72. The element which has unchanged properties when current direction is reversed

a)linear
b)bilateral
Ans: b

73. The output voltage is high in wat rectifier

a) HWR
b) FWR