A relay in which the measurement is performed by a stationary circuit and which has no moving parts is called

For high voltage ac circuit breakers, the rated short circuit current is passed for ___ seconds

Which of the following is not a type of contractor for circuit breakers?

Interrupting medium in a contactor for circuit breakers may be

Which of the following circuit breakers has the lowest voltage range?

Which of the following materials is not used in extinguishingthe arc in case of a circuit breaker?

The transient voltage that appears across the contacts of a circuit breaker at the instant of arc extinction is called

A relay used for protection of motors against overload

The number of cycles in which a high speed circuit breaker can complete its operation is

A material best suited for manufacturing of fuse wire is

In a circuit breaker, the current which exist at the instant of contact separation is called

A Merz-Price protection is suitable for

Interrupting capacity of a circuit breaker is usually expressed in

Which of the following contact point metals has the highest melting point?

Sparking occurs when a load is switched off because the circuit has

Sparking between contacts can be reduced by

An automatic device that operates at present values is called

The power factor of the arc in a circuit breaker is

Flame proofs switch gears are usually preffered in

Air used un air blast circuit breaker

In a circuit breaker, the time duration from the instant of the fault to the instant of energizing of the trip coil is known as

In a circuit breaker, the time duration from the instant of the fault to the extinction of the arc is known as

In a circuit breaker, the time duration from the instant of the fault to the instant of closing of contacts is known as

For a high speed circuit breaker the total clearing time is nearly

For a circuit breaker, "break" time is

Which relay is used for feeders?

Which relay is used for transmission line?

The value of fault current depends on

The advantage of grounding the neutral is

Over voltage surges in a power system may be caused by

The protection against over voltage due to lightning is provided by

A fuse is normally a

Which of the following is a conducting medium for electric current?

In a circuit breaker the contact space is ionized by

Which of the following are air break switching devices?

Which of the following is the demerit of SF6 circuit breaker?

The material used for bus bars should have

Fuse in motor circuit provides

The disadavantage of an underground system is

Series reactors are installed at strategic locations of a power system in order to