Explore topic-wise MCQs in Electric Drives.

This section includes 12 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.

Armature reaction is magnetizing in nature due to a purely resistive load in the synchronous motor.

A. True
B. False
Answer» C.
Discussion
2.

Armature reaction is demagnetizing in nature due to a purely capacitive load in the synchronous generator.

A. True
B. False
Answer» B. False
Discussion
3.

The phase difference between voltage and current in the choke coil.

A. 90°
B. 40°
C. 50°
D. 68°
Answer» B. 40°
Discussion
4.

Calculate the value of the duty cycle if the system is on for 1 sec and off for 0 sec.

A. 1
B. .4
C. .1
D. .6
Answer» B. .4
Discussion
5.

The slope of the V-I curve is 180o. Calculate the value of resistance. The graph is parallel to the x-axis.

A. 1.47 Ω
B. 1.81 Ω
C. 0 Ω
D. 4.12 Ω
Answer» D. 4.12 Ω
Discussion
6.

Calculate the reactive power in a 7.2545 Ω resistor.

A. 1.221 VAR
B. 2.611 VAR
C. 0 VAR
D. 1.997 VAR
Answer» D. 1.997 VAR
Discussion
7.

What is the unit of the distance?

A. m
B. m/s
C. atm/m
D. Volt
Answer» B. m/s
Discussion
8.

Calculate the reactive power in a 2.2 Ω resistor.

A. 1.2 VAR
B. 2.6 VAR
C. 0 VAR
D. 1.9 VAR
Answer» D. 1.9 VAR
Discussion
9.

Calculate the power factor if the power angle is 36.86°.

A. 0.8
B. .4
C. .6
D. 1
Answer» B. .4
Discussion
10.

The unit of oscillating power is VAR.

A. True
B. False
Answer» B. False
Discussion
11.

Cylindrical pole machines are more stable than salient rotor machines.

A. True
B. False
Answer» C.
Discussion
12.

What is the formula for the maximum active power in the cylindrical rotor synchronous machine? (Eb represents armature emf, Vt represents terminal voltage, δ represents rotor angle, X represents reactance)

A. Eb×Vt×sinδ÷X
B. Eb×Vt2÷X
C. Eb2×Vt×sinδ÷X
D. Eb×Vt÷X
E. Eb×Vt×sinδ÷Xb) Eb×Vt2÷Xc) Eb2×Vt×sinδ÷Xd) Eb×Vt÷X
Answer» E. Eb×Vt×sinδ÷Xb) Eb×Vt2÷Xc) Eb2×Vt×sinδ÷Xd) Eb×Vt÷X
Discussion