A dc shunt generator has full-load voltage regulation of 10% at rated speed of 1000 rpm.
If it is now driven at 1250 rpm, then its voltage regulation at full load would
A. be more than 10%
B. be less than 10%
C. remain unchanged
D. be 12.5%
Answer: A
Share your understanding of this question with the correct explanation.
The correct answer is A. The voltage regulation would be more than 10%.
Voltage regulation is a measure of the change in terminal voltage of a generator from no-load to full-load conditions, expressed as a percentage of the full-load voltage. It is typically specified at the rated speed of the generator.
In this case, the given DC shunt generator has a full-load voltage regulation of 10% at its rated speed of 1000 rpm. This means that the terminal voltage drops by 10% when the generator is operating at full load compared to no-load conditions.
If the generator is driven at a higher speed of 1250 rpm, it will have a higher induced voltage. However, the percentage drop in terminal voltage at full load will likely remain the same or increase. This is because the increase in speed affects the generator’s internal voltage characteristics, including the armature reaction and voltage drop across the armature resistance.
Therefore, the voltage regulation at full load would be more than 10% when the generator is driven at 1250 rpm.