| 1. | ........ relay is preferred for phase fault on short transmission line ? | |
|
Reactance
|
||
|
Impedence
|
||
|
Induction type
|
||
|
None of the above
|
||
View Answer
Discuss in Forum
Report Question| 2. | The single phasing relays are used for the protection of ? | |
|
single phase motors only
|
||
|
two single phase motors running in parallel
|
||
|
three phase motors
|
||
|
two phase motors only
|
||
| 3. | Wave trap is used to trap waves of ? | |
|
power frequencies
|
||
|
either of the above
|
||
|
higher frequencies entering generator or transformer units
|
||
|
none of the above
|
||
| 4. | The delay fuses are used for the protection of ? | |
|
light circuits
|
||
|
motors
|
||
|
fluorescent lamps
|
||
|
power outlet circuits
|
||
| 5. | Overheating of relay contacts or contact born out is due to ? | |
|
foreign matter on the contact surface
|
||
|
slow making and breaking of load circuit contacts
|
||
|
too low contact pressure
|
||
|
all of the above
|
||
| 6. | Directional relays are based on flow of ? | |
|
voltage wave
|
||
|
power
|
||
|
current
|
||
|
all of the above
|
||
| 7. | Resistance grounding is used for voltage between ? | |
|
11 kV to 33 kV
|
||
|
3.3 KV and 11kV
|
||
|
33 kV to 66 kV
|
||
|
none of the above
|
||
| 8. | Discrimination between main and back up protection is provided by the use of relays which are ? | |
|
fact
|
||
|
sensitive
|
||
|
slow
|
||
|
none of the above
|
||
| 9. | Which of the following statements is incorrect ? | |
|
The peak short current is (1.8 x root2) times the A.C. component
|
||
|
Lightning arrestors are used before the switchgear
|
||
|
The MVA at fault is equal to base MVA divided by per unit equivalent fault reactance
|
||
|
Shunt reactors are used as compensation reactors
|
||
| 10. | ........ transmission line has reflection coefficient as one ? | |
|
Long
|
||
|
Short-circuit
|
||
|
Open circuit
|
||
|
None of the above
|
||