MPSC PYQ

MPSC Rajyaseva 2023 CSAT — Question 39

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जेव्हा मोटारीतील यांत्रिक भार वाढतो, तेव्हा माघारी विद्युतगामकाचे काय होते ? What happens to the back emf, when the mechanical load on the motor increases ?

1)ते तसेच राहते / It remains the same
2)ते वाढते / It increases
3)ते कमी होते / It decreases✓ Correct
4)त्याचा मोटरवर काहीही परिणाम होत नाही / It has no effect on the motor

When mechanical load on a DC motor increases, the speed decreases, which in turn decreases the back emf (Eb) as Eb is directly proportional to speed.