Explore topic-wise MCQs in Dc Machines.

This section includes 7 Mcqs, each offering curated multiple-choice questions to sharpen your Dc Machines knowledge and support exam preparation. Choose a topic below to get started.

1.

Which function is performed by counter emf of a DC motor?

A. Exceeds supply voltage
B. Aids applied voltage
C. Helps in energy conversion
D. Regulates its armature voltage
Answer» D. Regulates its armature voltage
Discussion
2.

Armature resistance control method is used for the speed _____________

A. Above rated speed
B. Below rated speed
C. Can be used anywhere
D. Can t tell
Answer» C. Can be used anywhere
Discussion
3.

Field weakening control method is used for the speed _________

A. Above rated speed
B. Below rated speed
C. Can be used anywhere
D. Can t tell
Answer» B. Below rated speed
Discussion
4.

For very sensitive and wide speed control, which of the following method is preferred?

A. Armature control
B. Ward-Leonard control
C. Multiple voltage control
D. Field control
Answer» C. Multiple voltage control
Discussion
5.

Torque developed by a DC motor depends upon _____________

A. magnetic field
B. active length of the conductor
C. current flow through the conductors
D. Current, active length, no. of conductors, magnetic field all
Answer» E.
Discussion
6.

If a DC motor designed for 45 C ambient temperature is to be used for 55 C ambient temperature, then the motor ___________

A. Of lower HP should be selected
B. Of higher HP should be selected
C. Can be used for 50 C ambient temperature also
D. Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor
Answer» E.
Discussion
7.

Which of the following motor is used where high starting torque and wide speed range control is required?

A. All motors
B. Induction motor
C. Synchronous motor
D. DC motor
Answer» E.
Discussion