NTA UGC NET/JRF Exam, December-2019 (Electronic Science)

Total Questions: 100

41. For the system

The nature of the time response will be:

Correct Answer: C. Critically damped

42. Choose the statement which is incorrect.

Correct Answer: D. For a speed more than the base speed of a DC motor, the armature voltage is varied to control the speed while armature and field currents are maintained constant

43. The open loop transfer function of a unity feedback control system is given below

The system has:

Correct Answer: A. 1 breakaway point

44. The transfer function is given below

The number of roots with positive real part is:

Correct Answer: C. 2

45. SCR dildt protection is done by which of the following methods?

Correct Answer: D. Connecting inductance in series to SCR

46. In Schering bridge, the dissipation factor of a series RC circuit is defined as:

Correct Answer: C. Cotangent of the phase angle

47. In a crossed coil power factor meter the moving coils should be mounted on which type of shaft and at what angles to each other?

Correct Answer: B. same shaft and right angles

48. hich of the following expression is correct formulae of deflection sensitivity 'S' of а Cathode Ray Tube (CRT) if:

D = deflection on the fluorescent screen
L = distance from center of deflection plates
lᵈ = effective length of the deflection plates
d = distance between the deflection plates
Eᵈ = deflection voltage
Eₐ = accelerating voltage

Correct Answer: D.

49. A 500 kHz waveform is to be displayed by Digital Storage Oscilloscope (DSO) that samples at a rate of 50 Ms/Sec (50 Mega samples per second). The number of samples taken during one cycle is:

Correct Answer: D. 100

50. Velocity transducer essentially consists of one of the following:

Correct Answer: B. moving coil suspended in the magnetic field of a permanent magnet