# Speed - Rotor Resistance MCQ Questions & Answers

Speed - Rotor Resistance MCQs : This section focuses on the "Speed - Rotor Resistance". These Multiple Choice Questions (MCQs) should be practiced to improve the Speed - Rotor Resistance skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

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

Question 2

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

Question 3

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

Question 4

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

Question 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

Question 6

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 kgm2
B. 5.96 kgm2
C. 5.45 kgm2
D. 2.78 kgm2

Question 7

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

Question 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

Question 9

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.

Question 10

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

Question 11

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

A. Ns-Nr=constant
B. Ns*Nr=constant
C. Ns%Nr=constant
D. Ns+Nr=constant

Question 12

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 ?

Question 13

Calculate the active power in a 1.7 Ω 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

Question 14

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

A. 2 sec
B. 37 sec
C. 3 sec
D. 1 sec

Question 15

Calculate the useful power developed by a motor using the given data: Pin = 10 W, Ia = .6 A, Ra=.2 Ω. 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