# Brushless DC Motors MCQ Questions & Answers

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

Question 1

BLDC motor is analogous to ______________

A. Permanent magnet synchronous motor
B. DC motor
C. Rotating Transformer
D. Single-phase Induction motor

Question 2

Calculate peak-peak voltage if Vmax=45 V and Vmin=45 V.

A. 60 V
B. 30 V
C. 50 V
D. 0 V

Question 3

Calculate the average inductor current of the Boost converter if the load current is 7 A and duty cycle value is .8.

A. 36 A
B. 35 A
C. 34 A
D. 31 A

Question 4

Calculate the compensator rating required for cos(?)=.1.

A. 0.91 P.U
B. 0.99 P.U
C. 0.97 P.U
D. 0.92 P.U

Question 5

Calculate the electrical angle for 6 pole machine. (?m represents mechanical angle)

A. 4×?m
B. 5×?m
C. 2×?m
D. 3×?m

Question 6

Calculate the output power of the Buck converter if the supply voltage is 4 V and duty cycle value is .1 for 4 ? load.

A. 40 mW
B. 20 mW
C. 50 mW
D. 60 mW

Question 7

Calculate the output voltage of the Buck-Boost converter if the supply voltage is 14 V and duty cycle value is .85.

A. 79.3 V
B. 45.5 V
C. 86.5 V
D. 54.7 V

Question 8

Calculate the value of Crest factor if Vpeak=141 V and Vr.m.s=100 V for sinusoidal voltage.

A. 1.41
B. 2.38
C. 4.42
D. 5.58

Question 9

Due to low inertia, BLDC motors have __________

A. Faster acceleration
B. Slower acceleration
C. High-cost
D. Low cost

Question 10

In BLDC motor armature windings are placed on the stator side.

A. True
B. False

Question 11

In the biomedical instruments like artificial heart pumps, the motor used is ____________

A. DC shunt motor
B. DC series motor
C. Induction motor
D. BLDC motor

Question 12

The Hall effect sensor is used as the rotor position sensor for the BLDC motor.

A. True
B. False

Question 13

Which of the following are the types of BLDC motor?

A. Unipolar, Bipolar
B. Unipolar, PWM
C. Bipolar, PWM
D. Synchronous, Induction

Question 14

Calculate the compensator rating required for cos(Φ)=.1.

A. 0.91 P.U
B. 0.99 P.U
C. 0.97 P.U
D. 0.92 P.U

Question 15

Calculate the electrical angle for 6 pole machine. (θm represents mechanical angle)

A. 4×θm
B. 5×θm
C. 2×θm
D. 3×θm