The picture on the monitor of a computer is made up of tiny coloured dots called

The main advantage of using fractional pitch winding is to refuce

due to fractional pitch EMF can be approximately made into sine wave
losses due to harmonics reduced
saving in conductor material
mechanical strength of coil is increased.

Permittivity is expressed in terms of

Distribution transformers have good all day efficiency due to

all day efficiency is ratio of energy output to the energy input taken over 24 hour period.
design distribution transformer for max. efficiency occurring at the avarage output power.
performance of distribution transformer represent by all day efficiency.

The purpose of interpoles in DC machines is to nullify

interpoles is widely use to improve commutation
place between main poles fitted to yoke
functions:
to neutralize armature mmf in commutating zone
to produce some flux in commutating zone

Reactance relay is used to protect against