The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.
Answer : The single phasing relays are used for the protection of three phase motors.
Description : IDMT relays are used to protect the transformer against : (A) Internal short -circuits (B) Open circuits (C) External short circuits (D) Oil leakage
Answer : IDMT relays are used to protect the transformer against : External short circuits
Answer : Discrimination between main and back up protection is provided by the use of relays which are slow.
Answer : The relay with inverse time characteristic will operate within 5 to 10 sec.
Answer : Over voltage protection is recommended for hydro-electric generators, steam turbine generators, gas turbine generators.