1. A CT is connected in ___________________ with the line.
(A) series.
(B) across.
(C) not connected.
(D) both A and B.
Ans: (A) series.
Explanation:
A CT is connected in series with the line. PT is connected across the line. In CT number of turns is inversely proportional to current and in PT number of turns is inversely proportional to voltage.
2.In the relay coil which is used?
(A) Current transformer.
(B) Potential transformer.
(C) Power transformer.
(D) Instrument transformer.
Ans : (A) Current transformer.
Explanation:
CT used in the relay coil for reducing heavy current of a power circuit to a suitable value of operate the relay.
3. Mho relay is used for the protection of
(A) short lines.
(B) long lines.
(C) medium lines.
(D)none of these.
Ans : (B) long lines.
Explanation:
Mho relay is used for protection of long distance transmission lines.
4. What type of back up protection is used for alternators?
(A) IDMT relay.
(B) Buchholz relay.
(C) Mho relay.
(D) Impedance relay.
Ans: (A) IDMT relay.
Explanation:
IDMT stands for inverse definite minimum time lag (IDMT) relay. IDMT relay is used for over current and earth fault protection of alternators.
5. Merze price current scheme protection is used in
(A) transformer.
(B) alternator.
(C) both A and B.
(D) bus bars.
Ans: (C) both A and B.
Explanation:
Merze price current scheme protection is a differential protection used in transformer and alternators.