Explore topic-wise MCQs in Dc Machines.

This section includes 9 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.

For a DC motor taking 10kW power from 230V mains, having armature resistance and field resistance equal to 0.08 and 115 resp. The value of armature current is_____

A. 45.68 A
B. 43.48 a
C. 41.48 A
D. Data insufficient
Answer» D. Data insufficient
2.

What is the armature current for a DC generator if terminal voltage is observed to be 245V and open circuit voltage is equal to 250V, where armature resistance is 0.05 ?

A. 10A
B. 100A
C. 1KA
D. 1A
Answer» C. 1KA
3.

For a DC generator feeding 100kW power into 230V mains, having armature resistance and field resistance equal to 0.08 and 115 resp. The value of armature current is_____

A. 436.8 A
B. 434.8 a
C. 432.8 A
D. Data insufficient
Answer» B. 434.8 a
4.

What is the armature current for a DC motor if terminal voltage is 255V and open circuit voltage is equal to 250V, where armature resistance is 0.05 ?

A. 10A
B. 100A
C. 1KA
D. 1A
Answer» C. 1KA
5.

When torque of the electromagnetic origin is in the direction of rotation of armature, machine is said to be operating in which of the following mode?

A. Depends on other parameters
B. Generating
C. Motoring
D. Inducing
Answer» D. Inducing
6.

When Ea<Vt machine is said to be operating in which of the following mode?

A. Depends on the Shaft speed
B. Generating
C. Motoring
D. Inducing
Answer» D. Inducing
7.

4.When Ea>Vt machine is said to be operating in which of the following mode?

A. Depends on the Shaft speed
B. Generating
C. Motoring
D. Inducing
Answer» C. Motoring
8.

A 4-pole Dc wound machine is lap wound with 400 conductors. The pole shore is 20 cm long and average flux density over one-pole pitch is 0.4 T, the armature diameter being 30 cm. Here, motor is drawing 25 A current at 1500 rpm.
What is the available torque (N-m) at shaft?

A. 29.9
B. 59.8
C. 14.95
D. 44.85
Answer» B. 59.8
9.

Product of torque and mechanical angular velocity is_____

A. Ea/
B. Ea*Ia
C. /Ea
D. Can t tell
Answer» C. /Ea