Back EMF in Motor

Question

Why does back EMF tend to decrease as the rate of doing work increases.
When load increases it reduces the angular speed of motor as a result induce current due to back emf also decreases because the flux changes at a slower rate than before.

Anubhav Goel · Answer

increasing power of motor is not same as increasing load on motor. 
if you increase the power of motor its back emf would increase as it will consume more energy.

V=IR
Increasing power of motor means decreasing its resistance and hence increasing current.
If you simply increase load on same motor its back emf would decrease as because of reason given by you.
Now,
V=IR

While you increase load, resistance of motor remalns same , so only current is reduced on increasing load , hence decreasing back emf.

Back EMF in Motor

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