Q.1.
A protection system engineer is planning to provide the complete protection, he can achieve this by ___________
- a) three phase fault relays and two earth fault relays
- b) two phase fault relays and three earth fault relays
- c) a two phase fault relays and three earth fault relays
- d) a two phase fault relays and two earth fault relays
Q.2.
The given figure shows protection system scheme for one phase of generator. A high resistance fault occurs near the neutral end with the current distribution as marked. The slope of the relay isand pick-up current of 0.15A.
- a) True
- b) False
Q.3.
We need the biasing of differential relay biased to avoid mal operation when used for transformer protection due to ____________
- a) mismatch of CT
- b) saturation of
- c) difference in connection of both sides of CT
- d) current setting mismatch
Q.4.
If the specified fault setting for a winding is mentioned as 20%, then what can be inferred about it?
- a) If a terminal fault has its current limited to the full load rating, then 20% of winding from neutral end will be unprotected
- b) If a terminal fault has its current limited to the full load rating, then 80% of winding from neutral end will carry current
- c) If a terminal fault has its voltage limited to the full load rating, then 20% of winding from neutral end will be unprotected
- d) Any of the mentioned
Q.5.
The typical characteristic of the relay during loss of excitation is ____________
- a)
- b)
- c)
- d)
Q.6.
The standard system fault characteristic of the relay is _____________
- a)
- b)
- c)
- d)
Q.7.
A longitudinal differential protection on stator can detect inter-turn on the stator.
- a) True
- b) False
Q.8.
Bias is used in the relay protection to _______________
- a) provide balanced sharing of current
- b) reduce current level
- c) deivert the current
- d) none of the mentioned
Q.9.
Unbalancing of an alternator may occur due to ____________
- a) single phase fault
- b) unbalanced loading
- c) line breaking
- d) all of the mentioned
Q.10.
For the given earth fault for solidly earthed CT, the fault current as a percentage of the full load current is given as _______________
- a)
- b)
- c)
- d)