Explore topic-wise MCQs in Electric Drives.

This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Electric Drives knowledge and support exam preparation. Choose a topic below to get started.

1.

Choose the correct in the case of V/F control.

A. N<sub>s</sub>-N<sub>r</sub>=constant
B. N<sub>s</sub>*N<sub>r</sub>=constant
C. N<sub>s</sub>%N<sub>r</sub>=constant
D. N<sub>s</sub>+N<sub>r</sub>=constant
Answer» B. N<sub>s</sub>*N<sub>r</sub>=constant
Discussion
2.

Calculate the value of the time period if the frequency of the signal is .48 sec.

A. 2 Hz
B. 3 Hz
C. 7 Hz
D. 9 Hz
Answer» B. 3 Hz
Discussion
3.

Calculate the active power in a 1.7 resistor with 1.8 A current flowing through it.

A. 5.5 W
B. 5.1 W
C. 5.4 W
D. 5.7 W
Answer» B. 5.1 W
Discussion
4.

Calculate the active power in .an 18.064 H inductor.

A. 4.48 W
B. 17.89 W
C. 0 W
D. 25.45 W
Answer» D. 25.45 W
Discussion
5.

Calculate the active power in a 56 F capacitor.

A. 6.45 W
B. 0 W
C. 15.45 W
D. 14.23 W
Answer» C. 15.45 W
Discussion
6.

Calculate the active power in a 7481 H inductor.

A. 1562 W
B. 4651 W
C. 0 W
D. 4654 W
Answer» D. 4654 W
Discussion
7.

The slope of the V-I curve is 86.5 . Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. 16.34
B. 15.88
C. 48.43
D. 54.57
Answer» B. 15.88
Discussion
8.

Calculate the useful power developed by a motor using the given data: Pin = 10 W, Ia = .6 A, Ra=.2 . Assume frictional losses are 2 W and windage losses are 3 W.

A. 4.928 W
B. 1.955 W
C. 1.485 W
D. 1.488 W
Answer» B. 1.955 W
Discussion
9.

Calculate the time period of the waveform y(t)=87cos( t+289 4).

A. 2 sec
B. 37 sec
C. 3 sec
D. 1 sec
Answer» B. 37 sec
Discussion
10.

Calculate the moment of inertia of the thin spherical shell having a mass of 7.8 kg and diameter of 145.6 cm.

A. 2.72 kgm<sup>2</sup>
B. 5.96 kgm<sup>2</sup>
C. 5.45 kgm<sup>2</sup>
D. 2.78 kgm<sup>2</sup>
Answer» B. 5.96 kgm<sup>2</sup>
Discussion
11.

Calculate the moment of inertia of the tennis ball having a mass of 7 kg and diameter of 152 cm.

A. 3.55 kgm<sup>2</sup>
B. 4.47 kgm<sup>2</sup>
C. 2.66 kgm<sup>2</sup>
D. 1.41 kgm<sup>2</sup>
Answer» D. 1.41 kgm<sup>2</sup>
Discussion
12.

Calculate the value of the angular acceleration of the motor using the given data: J = .1 kg-m2, load torque = 45 N-m, motor torque = 55 N-m.

A. 100 rad/s<sup>2</sup>
B. 222 rad/s<sup>2</sup>
C. 300 rad/s<sup>2</sup>
D. 400 rad/s<sup>2</sup>
Answer» B. 222 rad/s<sup>2</sup>
Discussion
13.

Calculate the active power developed by a motor using the given data: Eb = 5.5 V and I = .5 A.

A. 2.75 W
B. 2.20 W
C. 5.30 W
D. 5.50 W
Answer» B. 2.20 W
Discussion
14.

40 V, 7 A, 70 rpm DC separately excited motor having a resistance of 0.3 ohms excited by an external dc voltage source of 4 V. Calculate the torque developed by the motor on half load.

A. 18.10 N-m
B. 4.24 N-m
C. 40.45 N-m
D. 52.64 N-m
Answer» B. 4.24 N-m
Discussion