Question { NCC, 112899 }

what is the function of anti-pumping in circuit breaker?

Answer

The contacts of this relay prevent uncontrolled discharging
of the closing spring, if the closing signal remains
complete up to the breaker. If the circuit remains
complete, the closing spring would discharge under the
wrong conditions, this is called pumping.

Question { 35146 }

what is AVR in alternator how its work?

Answer

AVR stands for Automatic Voltage Regulator.
So it is a regulating system which measure the generator
output then comparise with a reference value and generate a
positive or negative output to the excitation system to
decrease or increase the excitation to increase or decrease
the generator output voltage.