a) Impulse voltage b) Insulation failure c) Mechanical vibration d) Magnetostriction force e) Loose connection Ans: (b)
a) External fault currents b) Internal fault currents c) Magnetizing currents d) None of the above Ans: (c)
a) Does not exceed 15% of fundamental b) Exceed 15% of fundamental c) Exceed 14.4% of fundamental d) Exceed 17.3% of fundamental Ans: (b)
a) External short circuits b) Internal short circuits c) Heavy overloads d) All the above cases Ans: (b)
a) Shunt reactors are used for power factors improvement b) Shunt reactor are used to control the line voltage c) Shunt reactors are used to reduce the line impedance d) Shunt reactors are used to eliminate line to ground capacitance Ans: (a)
a) An over-voltage relay connected across the secondary of the transformer b) An over-current relay connected across the secondary of the transformer c) An under-voltage relay connected across the secondary of the transformer d) None of the above Ans: (a)
a) True b) False Ans: (a)
a) True b) False Ans: (b)
a) Impedance relays b) Reactance relays c) MHO relays d) None of the above Ans: (a)
a) Impedance relays are best suited b) MHO relays best suited c) Reactance relays are best suited d) Split-phase relays are best suited Ans: (b)