Which of the following power distribution system gives better reliabity ?

The bus bar zone faults are generally

Buchholz relay causes

A fuse wire should have

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

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.