a) Air blast circuit breaker. b) Oil C.B. c) Vacuum C.B. d) Any one of the above. Ans: (c)
a) R.m.s. value b) Peak value c) Average value d) Both r.m.s. and peak value. Ans: (b)
a) Certain conclusions regarding the continuous ageing of an insulation can be drawn. b) The stress distribution is a representation of the service condition. c) Standardization on the magnitude of voltage to be applied is available. d) The stresses do not damage the coil end insulation. Ans: (a)
a) Non-directional relays at the source end and directional relays at the load end. b) Non-directional relays at both the ends. c) Directional relays at the source end and non-directional at the load end. d) Directional relays at both the ends. Ans: (a)
a) 25 amps b) 45 amps c) 50 amps d) None of the above Ans: (d)
a) Its leakage resistance should be greater than the surge impedance. b) Three-phase and two-earth fault relays are required. c) Two-phase and two-earth fault relays are required. d) Two-phase and one-earth fault relays are required. Ans: (b)
a) 400 kΩ b) 40 kΩ c) 5 kΩ d) 4 kΩ Ans: (c)
a) Increases in case of OCB. b) Decreases in case of OCB. c) Interruption is always at first current zero (in OCB) d) None of the above. Ans: (a)
a) Positive sequence b) Zero sequence c) Negative sequence d) Both (a) and (b) Ans: (d)
a) High sequence b) High impedance c) Low resistance d) Low impedance Ans: (c)