Top 250+ Solved Testing and Commissioning of Electrical Equipment’s MCQ Questions Answer
Q. 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
Q. Shunt capacitance is neglected while considering
a. short transmission line
b. medium transmission line
c. long transmission line
d. medium and long transmission lines
Q. The time of closing the cycle, in modern circuit breakers is
a. 0.003 sec
b. 0.001 sec
c. 0.01 sec
d. 0.10 sec
Q. Insulation resistance of high voltage circuit breakers is more than
a. 1 mega ohms
b. 10 mega ohms
c. 100 mega ohms
d. 500 mega ohms
Q. H.R.C. fuses provide best protection against
a. overload
b. reverse current
c. open-circuits
d. short-circuits
Q. The delay fuses are used for the protection of ________.
a. motors
b. power outlet circuits
c. fluorescent lamps
d. light circuits
Q. Which of the following is the least expensive protection for overcurrent is lowvoltage system ?
a. Rewireable fuse
b. Isolator
c. Oil circuit breaker
d. Air break circuit breaker
Q. Resistance grounding is used for voltage between
a. 33kVto66kV
b. HkVto33kV
c. 3.3kVandllkV
d. none of the above
Q. 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
Q. In Railway applications ______ circuit breaker is used.
a. SFe
b. bulk oil
c. minimum oil
d. air break
Q. To protect most of the electrical equipment handling low power, the types of relaysused are
a. thermocouple
b. electronic and bimetallic
c. both (A) and (B)
d. none of the above
Q. Wave trap is used to trap waves of
a. power frequencies
b. higher frequencies entering generator or transformer units
c. either of the above
d. none of the above
Q. Ungrounded neutral transmission system is not recommended because of system
a. insulation being overstressed due to over voltages
b. insulation overstress may lead to failure and subsequent phase to phase faults
c. being inadequately protected against ground fault
d. all of the above
Q. The reflection co-efficient at the open circuited end of a transmission line.
a. zero
b. infinity
c. unity
d. none of the above