SYNCHRONOUS MOTORS QUIZ

variable supply voltage

variable frequency

windage friction

variable load

A higher value of stability limit

All of the listed here

A higher synchronizing power which makes the machine less sensitive to load variations

A small value of inherent regulation

Provinding damper winding

Pony motor

All of the listed here

Dc compound motor

not start

run with excessive vibrations

take less than the rated load

run at 2/3 of synchronous speed

Rise in winding temperature

Shorting of coils

Eddy current flow

Increased core losses

0°

30°

45°

75°

vector sum of Eb and V

arithmetic difference of Eb and V

arithmetic sum of Eb and V

vector difference of Eh and V

induction motor torque in damper winding

All of the listed here

induction motor torque in field winding

eddy current and hysteresis torque in pole faces

Under excited

Normally excited

Over excited

None of the listed here

changing frequency

changing the supply voltage

changing the load

using brakes