NTA UGC NET/JRF Exam, June -2021 (Electronic Science)

Total Questions: 100

31. The absolute maximum operating frequency of a converter grade SCR whose turn on time and turn off time are 3 µs and 200 µS respectively is:

Correct Answer: C. 4.9 kHz

32. A single phase 220V, 1kW electric room radiator is connected across 220V supply through a triac. For a delay angle of 90°, the value of power dissipated by the radiator is:

Correct Answer: D. 500 W

33. Read the statement.

Correct Answer: A.

34. À 10kW carrier is simultaneously modulated by two modulating signals corresponding to a modulation index of 40% and 30%, respectively. The total radiated power will be:

Correct Answer: C. 11.25 kW

35. If an amplitude modulated wave 10[1 + 0.6 cos 2π10³t] cos2π.10If an amplitude modulated wave 10[1 + 0.6 cos 2π103t] cos2π.106.t is to be detected by a linear diode detector, then the time constant will be:.t is to be detected by a linear diode detector, then the time constant will be:

Correct Answer: В. 0.17 msec

36. If the in-phase and quadrature components in an M-ary PSK system are permitted to be independent, then this scheme becomes a:

Correct Answer: C. M-ary QAM

37. Which of the following statements is correct?

Correct Answer: D. Compensation of an instrument improves its dynamic characteristics.

38. The Q of the coil using series connection measurement method is given by which of the following equations?

Correct Answer: B.

39. Using a 10-bit conversion, the dynamic range available from an input signal sampled for 4 seconds at a sampling rate of 20 kHz is:

Correct Answer: A. 60 dВ

40. If Nᵢ and Nₒ are the corresponding speeds of input and output shafts of a Gear Dynamometer, respectively, and η is overall mechanical efficiency, the input torque 'τᵢ' applied by mass 'm' at a distance 'R' is given by:

Correct Answer: B.