Question

Calculate the voltage regulation in the synchronous machine if the no-load voltage is 12 V and the full load voltage is 15V.

(a) -20%

(b) -40%

(c) -60%

(d) -80%

This question was addressed to me at a job interview.

This key question is from Induction Motors topic in portion Speed Control of Direct Current Motors & Induction Motors of Electric Drives

Answer 1

The correct answer is (a) -20%

The best explanation: Voltage regulation is defined as the fluctuation in the load voltage when the load is varied from no-load to full load. V.R(%) = (No-load voltage-Full load voltage) ÷ Full load voltage=12-15÷15 = -20%.