The purpose of embedding the damper winding in the pole face of a synchronous motor is to

under steay state:
P= (E V sinδ)/ X
change in load on motor, δ adjust to new value
rotor oscillate about its final equilibrium load angle called hunting.
cause:
sudden change in load
fault in supply system
sudden change in field current
remedies:
using flywheel
using damper bar

The form factor in AC means the ration of

The main criterion for the design of a distributor is

Reactance relay is used to protect against

The motor used in celling fans is

Starting method of 1 phase I.M.
Split phase starting
Shaded pole starting
types of 1 phase I.M.
Resistor split phase motor
capacitor spit phase motor
Resistor split phase motors have poor starting torque
capacitor split phase motor, capacitor connect series with auxiliary winding make angle 90˚ result in optimum starting torque.

Permittivity is expressed in terms of