For cost and safety, the outdoor substations are installed for voltages above_________________?
A. 11 kV
B. 33 kV
C. 60kV
D. 110kV
Switchgear and Protection
Short-circuit currents are due to_______________?
Short-circuit currents are due to_______________?
A. single phase to ground faults
B. phase to phase faults
C. two phase to ground faults
D. three phase faults
E. any of these
A.C. network analyser is used to solve problems of_______________?
A.C. network analyser is used to solve problems of_______________?
A. load flow
B. load flow and short-circuit
C. load flow and stability
D. load flow, short-circuit and stability
E. none of the above
To reduce short circuit fault currents are used_____________?
To reduce short circuit fault currents are used_____________?
A. reactors
B. resistors
C. capacitors
D. none of the above
Induction cup relay is operated due to changes in________________?
Induction cup relay is operated due to changes in________________?
A. current
B. voltage
C. impedance
D. all of the above
When a wave propagates on a transmission line, it suffers reflection several times at_____________?
When a wave propagates on a transmission line, it suffers reflection several times at_____________?
A. tapg
B. load end
C. sending end
D. sending and other end
E. all of the above
The reflection co-efficient at the open circuited end of a transmission line___________?
The reflection co-efficient at the open circuited end of a transmission line___________?
A. zero
B. infinity
C. unity
D. 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______________?
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
H.R.C. fuses provide best protection against________________?
H.R.C. fuses provide best protection against________________?
A. overload
B. reverse current
C. open-circuits
D. short-circuits
To protect most of the electrical equipment handling low power, the types of relays used are______________?
To protect most of the electrical equipment handling low power, the types of relays used are______________?
A. thermocouple
B. electronic and bimetallic
C. both (A) and (B)
D. none of the above