A. merz price percentage differential protection
B. mho and ohm relays
C. horn gaps and temperature relays
D. earth fault and positive sequence relays
Related Mcqs:
- relays are used for phase faults on long line?
A. Impedance
B. Reactance
C. Either of the above
D. None of the above - A transmission line is protected by_____________?
A. inrush protection
B. distance protection
C. time graded and current graded over current protection
D. both (B) and (C)
E. none of the above - The current zero interruption, in oil and air blast circuit breakers, is achieved by_______________?
A. lengthening of the gap
B. cooling and blast effect
C. both A. and B
D. deionizing the oil with forced air
E. none of the above - Interruption of large currents by relay requires______________?
A. arc suppressing blow out coils
B. wide separation of the opened contacts
C. high speed opening of contacts
D. all of the above - Which of the following medium is employed for extinction of arc in air circuit breaker?
A. Water
B. Oil
C. Air
D. SF6 - In a circuit breaker the basic problem is to________________?
A. maintain the arc
B. extinguish the arc
C. transmit large power
D. emit the ionizing electrons - For the protection of power station buildings against direct strokes the requirements are___________?
A. interception
B. interception and conduction
C. interception, conduction and dissipation
D. interception, conduction, dissipation and reflection
E. none of the above - The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to______________?
A. lubricate the contacts
B. insulate the contacts from switch body
C. extinguish the arc
D. all of the above
E. none of the above - A _________ is used to measure the stator % winding temperature of the generator?
A. thermocouple
B. pyrometer
C. resistance thermometer
D. thermometer - H.R.C. fuse, as compared to a rewirable fuse, has_________________?
A. no ageing effect
B. high speed of operation
C. high rupturing capacity
D. all of the above
