Explore topic-wise MCQs in Dc Machines.

This section includes 6 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 given DC series generator with critical resistance equal to 100 , armature resistance is equal to 50 , and series field resistance is equal to 20 , is connected across load of 50 . What will be the load voltage?

A. 20 kV
B. 0 V
C. 2 kV
D. Data insufficient
Answer» C. 2 kV
Discussion
2.

For a DC series generator what is the condition for self-excitation?

A. (R<sub>a</sub>+R<sub>se</sub>) &gt; RC
B. (R<sub>SE</sub>+R<sub>se</sub>+R<sub>L</sub>) &lt; R<sub>C</sub>
C. (R<sub>SE</sub>+R<sub>se</sub>+R<sub>L</sub>) &gt; R<sub>C</sub>
D. (R<sub>se</sub>+R<sub>L</sub>) &gt; R<sub>C</sub>
Answer» D. (R<sub>se</sub>+R<sub>L</sub>) &gt; R<sub>C</sub>
Discussion
3.

For series DC generator, internal/external characteristic start from ____________

A. Positive non-zero voltage
B. Zero voltage
C. Negative non-zero voltage
D. Can start from anywhere
Answer» C. Negative non-zero voltage
Discussion
4.

External characteristic differ from internal characteristic in DC series motor by ______

A. I<sub>a</sub> *(R<sub>a</sub> + R<sub>SE</sub>)
B. I<sub>a</sub> *R<sub>a</sub>
C. I<sub>a</sub> *R<sub>SE</sub>
D. If *R<sub>SE</sub>
Answer» B. I<sub>a</sub> *R<sub>a</sub>
Discussion
5.

7.How compounding level in a compound machine is adjusted?

A. By adding variable resistance in series with series field resistance
B. By adding variable resistance in parallel with series field resistance
C. By adding fixed resistance in parallel with series field resistance
D. By adding fixed resistance in series with series field resistance
Answer» C. By adding fixed resistance in parallel with series field resistance
Discussion
6.

Characteristics of separately excited DC generator are drawn by keeping _____

A. Field current and speed both constant
B. Field current and speed both variable
C. Field current constant and speed variable
D. Field current variable and speed constant
Answer» C. Field current constant and speed variable
Discussion