Questions
61
A.C. network analyser is used to solve problems of
Answer: load flow, short-circuit and stability
63
The short circuit in any winding of the transformer is the result of
Answer: impulse voltage
64
For which of the following protection from negative sequence currents is provided ?
Answer: Generators
65
Relay is preferred for phase fault on short transmission line.
Answer: Reactance
66
For which of the following ratings of the transformer differential protection is recommended ?
Answer: equal to and above 5 MVA
68
The single phasing relays are used for the protection of
Answer: three phase motors
69
Which of the following parameter can be neglected for a short line ?
Answer: Capacitance
70
Which of the following circuit breakers has high reliability and minimum maintenance ?
Answer: Circuit breaker with SF6 gas
72
The inverse definite mean time relays are used for over current and earth fault protection of transformer against
Answer: internal short-circuits
73
Air blast circuit breakers for 400 kV power system are designed to operate in
Answer: 50 millisecond
74
Series capacitors are used to
Answer: compensate for line inductive reactance
75
If the fault occurs near the impedance relay, the VII ratio will be
Answer: lower than that of if fault occurs away from the relay
76
The torque produced in induction type relay (shaded pole structure) is
Answer: inversely proportional to the square of the current
77
The inductive interference between power and communication line can be minimized by
Answer: both (a) and (b)
78
The power loss is an important factor for the design of
Answer: transmission line
