Q.1
Discrimination between main and back up protection is provided by the use of relays which are
  • fact
  • sensitive
  • slow
  • none of the above
Q.2
Short-circuit currents are due to
  • single phase to ground faults
  • phase to phase faults
  • two phase to ground faults
  • three phase faults
  • E. any of these
Q.3
Transmission line has reflection coefficient as one.
  • Open circuit
  • Short-circuit
  • Long
  • None of the above
Q.4
The time of closing the cycle, in modern circuit breakers is
  • 0.003 sec
  • 0.001 sec
  • 0.01 sec
  • 0.10 sec
  • E. none of the above
Q.5
Thermal circuit breaker has
  • delayed trip action
  • instantaneous trip action
  • both of the above
  • none of the above
Q.6
A thermal protection switch can protect against
  • short-circuit
  • temperature
  • overload
  • over voltage
0 h : 0 m : 1 s