Question
Physics Question on Electromagnetic induction
The back emf in a dc motor is maximum when the motor has just been switched on When motor is switched on it has maximum speed
A
If both assertion and reason are true and reason is the correct explanation of assertion
B
If both assertion and reason are true but reason is not the correct explanation of assertion
C
If assertion is true but reason is false
D
If both assertion and reason are false
Answer
If both assertion and reason are false
Explanation
Solution
Back emf is actually the induced emf produced in motor. When motor is just switched on, the magnitude of back emf is quite small due to the low speed of the motor. But the magnitude of back emf is very large at break (when electric supply fails suddenly, while the motor is running)