Top 150+ Solved Switch Gear and Protection MCQ Questions Answer
Q. Protective relays can be designed to respond to
a. Light intensity, impedance
b. Temperature, resistance, reactance
c. Voltage and current
d. All of these
Q. On what factor does the operating speed of the relay depend upon?
a. Rate of flux built up
b. Armature core air gap
c. spring tension
d. All of these
Q. What does the third part consist of?
a. Primary winding of a current CT which is connected in series with the line to be protected.
b. Secondary of the CT and the operating coil.
c. Tripping circuit.
d. All of these.
Q. Which component ensures the safety of the line from damage?
a. Relay
b. Circuit breaker
c. Bus bar
d. Current tr
Q. Plug setting of a electromagnetic relay can be altered by varying
a. Number of ampere turns
b. Air gap of magnetic path
c. Adjustable back stop
d. None of these
Q. the most efficient torque producing actuating structure for theinduction type relays is
a. Shaded pole structure
b. Watt hour meter structure
c. Induction cup structure
d. Single induction loop structure
Q. If the power factor is zero, the active recovery voltage will be
a. minimum
b. 0.5
c. 0.707
d. Maximum.
Q. Which of the following is not a part of the circuit breaker?
a. Explosion pot
b. Fixed and moving contacts
c. Conservator
d. Operating mechanism.
Q. Which of the following circuit breaker will produce the least arc energy?
a. Minimum oil circuit breaker
b. Air blast circuit breaker
c. Plain oil circuit breaker
d. All will produce same energy.
Q. For a circuit breaker 'break time' is
a. Same as opening time
b. Opening time + arc duration
c. Opening time + arc duration + resistor current duration.
d. none
Q. The breaking capacity of a circuit breaker in MVA (3 phase) is given by
a. Rated service voltage x rated symmetrical current
b. 1.1 x rated service voltage x rated symmetrical current
c. (2)1/2 x rated service voltage x rated symmetrical current
d. (3)1/2x rated service voltage x rated symmetrical current.
Q. Which relay is used for feeders?
a. MHO relay
b. Translay relay
c. Merz price protection
d. Buchholz relay.
Q. Which of the following relays is used on transformers?
a. Buchholz relay
b. MHO relay
c. Merz price relay
d. None of the above.