Inverse definite minimum time lag relay is also called ___________ (A) pilot relay. (B) differential relay. (C) over current relay. (D) directional overcurrent relay.

Inverse definite minimum time lag relay is also called ___________
(A) pilot relay. (B) differential relay.
(C) over current relay. (D) directional overcurrent relay.
by

1 Answer

Answer :

Ans: B
Inverse definite minimum time lag relay characteristic is inverse but minimum time is
fixed. The operating time is inversely proportional to the magnitude of actuating
quantity.
by

Related questions

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Last Answer : Directional phase or earth fault protection of ring-mains, parallel transformers, transformer feeders, parallel feeders etc., employing the time graded principle.; This relay comprises an inductive ... induction disc unit. The directional unit is normally provided with voltage polarising coils. 

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Last Answer : Answer: B

What is the characteristic of inverse time over current relay?

Description : What is the characteristic of inverse time over current relay?  

Last Answer : If the fault current increases the time of the operation of the relay will be decreases.  

Purpose of over current relay (Inverse); type- CDG

Description : Purpose of over current relay (Inverse); type- CDG  

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The inverse definite mean time relays are used for over current and earth fault protection of transformer against?

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Description : In a static over-current relay, inverse time characteristics are obtained by   (a) A differentiating circuit (b) An integrating circuit (c) A transistor amplifier (d) A transistor switch

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Description : Explain construction and operation of induction type directional over current relay.

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In the induction type directional over current relay, when a short-circuit occurs in the circuit

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What are the features of directional relay?

Description : What are the features of directional relay?

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A circuit breaker for a 300 KW alternator is rated at 470 amperes of full continuous load. The amount of overcurrent allowed is 125%. Which of the following conditions will trip the breaker? A. Sustained current flow of 470 amperes. B. Sustained current flow of 500 amperes for 10 minutes. C. Momentary starting load of 550 amperes. D. Sustained current flow of 590 amperes.

Description : A circuit breaker for a 300 KW alternator is rated at 470 amperes of full continuous load. The amount of overcurrent allowed is 125%. Which of the following conditions will trip the breaker? A. ... 10 minutes. C. Momentary starting load of 550 amperes. D. Sustained current flow of 590 amperes.

Last Answer : Answer: D

A series resistance is added to the over-current relay in a bus bar differential protection scheme which:

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Description : Mention any two applications of differential relay.

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Description : Will main generator differential relay pick up for generator earth faults? 

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The greatest single cause of electrical failures is ______. A. the breakdown of insulation B. overcurrent C. high inductance D. too frequent testing

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Last Answer : Answer: A

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When voltage increases then current also increases then what is the need of over voltage relay and over current relay? Can we measure over voltage and over current by measuring current only?

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When voltage increases then current also increases then why we need of over voltage relay and over current relay? Can we measure over voltage and over current by measuring current only?

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The relay with inverse time characteristic will operate within?

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Description : If the phase -angle of the voltage coil of a directional relay is 50°, the maximum torque angle of the relay is: (A) 130° (B) 100° (C) 50° (D) 25°

Last Answer : If the phase -angle of the voltage coil of a directional relay is 50°, the maximum torque angle of the relay is: 50°

In the illustration, if one of the devices labeled 'TURB' should fail the ___________. EL-0003 A. device labeled 'EXC' will drive the alternator B. device labeled 'BKR' for that alternator should automatically open because of the reverse power relay C. operator must open all the devices labeled 'BKRS' to reduce the load on the remaining turbo-alternator D. emergency generator should automatically start and be placed on line to supply emergency load centers

Description : In the illustration, if one of the devices labeled 'TURB' should fail the ___________. EL-0003 A. device labeled 'EXC' will drive the alternator B. device labeled 'BKR' for that ... -alternator D. emergency generator should automatically start and be placed on line to supply emergency load centers

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A circuit is protected from overheating by a/an ___________. A. pyrometer B. thermal overload relay C. magnetic contactor D. overload transformer

Description : A circuit is protected from overheating by a/an ___________. A. pyrometer B. thermal overload relay C. magnetic contactor D. overload transformer

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To overcome the lag in the operating speeds of the I/O device and the processor we use ___________ a) BUffer spaces b) Status flags c) Interrupt signals d) Exceptions

Description : To overcome the lag in the operating speeds of the I/O device and the processor we use ___________ a) BUffer spaces b) Status flags c) Interrupt signals d) Exceptions

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What is the direction of current through the load resistor in the circuit shown in the illustration? EL-0085 A. Always from point 'Z' to the grounded end. B. Always from the grounded end to point 'Z'. C. It depends on the instantaneous polarity at point 'W'. D. It cannot be determined without a directional ammeter.

Description : What is the direction of current through the load resistor in the circuit shown in the illustration? EL-0085 A. Always from point 'Z' to the grounded end. B. Always from the grounded end to ... on the instantaneous polarity at point 'W'. D. It cannot be determined without a directional ammeter.

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Possible phase relationships between voltage and current in an alternating current circuit include which of the following conditions? A. Current and voltage may be in phase. B. Current may lead the voltage. C. Current may lag the voltage. D. All of the above.

Description : Possible phase relationships between voltage and current in an alternating current circuit include which of the following conditions? A. Current and voltage may be in phase. B. Current may lead the voltage. C. Current may lag the voltage. D. All of the above.

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At dead short circuit at terminals of Alternator then the current I is a) ZPF Lag b) ZPF lead c) Unity power factor d) 0.8 Power factor lag

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Description : A differential relay measures the vector difference between (a) two currents (b) two voltages (c) two or more similar electrical quantities (d) none of the above

Last Answer : (c) two or more similar electrical quantities

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Description : In a biased differential relay, the bias is defined as the ratio of  A) Number of turns of restraining coil and operating coil B) Operating coil current and restraining coil current C) Faulteurrent and operating coil current D) Fault current and restraining coil current

Last Answer : In a biased differential relay, the bias is defined as the ratio of Number of turns of restraining coil and operating coil 

The purpose of the restraining coil in a biased differential relay is

Description : The purpose of the restraining coil in a biased differential relay is  (A) To reduce CT saturation during fault.  (B) To increase the sensitivity of the relay.  (C) To match the transformation ratio.  (D) To limit the spill current through the relay during heavy external fault.

Last Answer : d

A differential relay measures the vector difference between?

Last Answer : A differential relay measures the vector difference between two or more similar electrical quantities.

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Description : In accordance with Coast Guard Regulations (46 CFR), each battery operated relay-controlled lantern must _____________. A. be readily portable B. contain a dry cell battery having a minimum capacity of ... automatic battery charger to maintain the battery in a fully charged state D. all of the above

Last Answer : Answer: C

What is a differential amplifier? Also, explain CMRR.

Description : What is a differential amplifier? Also, explain CMRR.

Last Answer : Differential Amplifier: The amplifier, which is used to amplify the voltage difference between two input-lines neither of which is grounded, is called differential amplifier. This reduces the amount of noise ... , CMRR would be infinite because in that case common mode voltage gain would be zero.

What is the difference between over voltage relay and over current relay?

Description : What is the difference between over voltage relay and over current relay?

Last Answer : A:The current increases not only for over voltages but also for under voltage(As most of the loads are non-linear in nature). So,the over voltage protection & over current protection are completely ... , for a better protection of the system.It should have both over voltage & over current relay.