A compound dc generator is delivering full load current at ___

Electrical Engineering MCQ Electrical Machines MCQ
1

A compound dc generator is delivering full load current at a terminal voltage of 230 V.

Its series-field winding gets short circuited.

If its terminal voltage

  1. becomes more than 230 V, it is over-compounded generator
  2. becomes more than 230 V, it is differentially compounded generator
  3. becomes less than 230 V, it is overcompounded generator
  4. becomes less than 230 V, it is differentially compounded generator
  5. becomes less than 230 V, it is level compounded generator

From these, the correct answer is

A. 1, 4, 5
B. 2, 3, 5
C. 1, 4
D. 2,3

Show Answer

Answer: B

Share your understanding of this question with the correct explanation.

2

I apologize for the confusion in my previous response. The correct answer is indeed C. commutator.

DC generators are designed with a maximum limit on the armature voltage they can generate, and one of the main factors limiting this voltage is the commutator. The commutator is a mechanical device that facilitates the conversion of alternating current within the armature windings into direct current at the output terminals of the generator.

The commutator consists of multiple segments that make contact with the brushes, and it must handle the voltage and current transitions during the commutation process. Exceeding the voltage limit can result in issues such as excessive sparking, deterioration of the commutator surface, and poor commutation, leading to reduced generator performance and reliability.

Therefore, DC generators are typically designed with armature voltages that do not exceed certain limits determined by the capabilities of the commutator, ensuring proper operation and longevity of the generator.