Power Systems Objective Questions & Answers – Set 16

The use of high speed circuit breakers

Lightning arresters are used to protect electrical equipment against

Mho relay is used for protection of

In a power system with negligible resistance, the fault current at a point is 8.00 pu. The series reactance is to be included at the fault point to limit the short circuit. current to 5.00 pu is

IF the time of operation of a relay for unity TMS is 10 sec then the time of operation for 0.5 TMS is

The insulation of modern EHV is designed based on

Keeping in view the cost and overall effectiveness, the following circuit breaker is best suited for capacitor bank switching?

Buchholz relay is used for protection of

The shape of the disc of an induction disc relay is

Length of the cable is doubled, its capacitance C will be

What type of back up protection is used for alternators?

Where the voltage is high and current to be interrupted is low, Which of following the breaker is preferable?

In a 400 kV power network, 360 kV is recorded at 400 kV bus. The reactive power absorbed by a shunt reactor for 50 MVAr, 400 kV connected at the bus is

In an induction relay for a particular current setting the operating time 4 sec. When the time multiplier setting is 0.8 if the time multiplier setting is rest to 1 the operating time is

The most suitable circuit breaker for short line fault without switching resistor is

Zero sequence currents can flow from a line into a transformer bank if the windings are in

Merze price current scheme protection is used in

The rate of rise of restricting voltage depends upon the

A 60 Hz, 320 Km loss less line has sending end voltage 1.0 pu. The receiving end voltage on no-load is

Resistance switching in normally employed in

Mho relay is used for the protection of

What will be the ratio of the C.T. on the H.V side of a 3 - φ star / delta 33 / 11 kV transformer if the protecting CT on the LV side has a ratio of 300 : 5 ?

The ratio of reset to pick up current for an induction cup relay is approximately

Out of the following plant categories which is not the base load power plant?

In a biased differential relay the bias is defined as the ratio of

If the time of operation of a relay for unity TMS is 10 sec. the time of operation of 0.5 TMS will be _______________ secs.

Main bus bar protection scheme is /are

The unit protection scheme provides

To prevent maloperation of deferentially connected relay while energizing a transformer, the relay restraining coil is biased with

Capacitance voltage transformer ( CVT ) is used to