68.

69,

70.

71.

72,

73.

74,

The ratio of OC Voltage to SC current keeping the field excitation constant in an alternator is
called .

(ಹ) Synchronous resistance (8) Synchronous inductance

(ಲ) Synchronous capacitance (D) Synchronous impedance

Hunting in an alternator can be prevented by
(A) Injecting harmonics (8) Damper bars
(ಲ) Inter poles (D) None of the above

An alternator connected to a 440 V, 50 Hz supply will run at higher speed when number of
poles are -

வ 2 ® 4 © 6 2 8

In a 3 phase alternator a field current of 100 A produces a full load armature current of
400 A on short circuit and 1730 V on open circuit. The value of synchronous impedance is
Q.

(ಹ) 2 ൫ 2.5 ര 4 ©

When two or more protective devices are used for the protection of the same circuit, the
correct operation of the correct device on occurance of a fault is called

(ಹ) Discrimination (8) Expulsion (ಲ) 200 ೦೬ (D) Rupture

The transient voltage which appears across the circuit breaker contacts, at the instant of arc
being extinguished is known as

(ಹ) Recovery voltage (B) Restriking voltage
(ಲ) System voltage (D) Normal voltage

Which of the following is an example for a distance relay ?

(ಹ) Impedance relay (B) Elliptical relay
(9) Quadrilateral relay (D) All the above
11 029/ 2018

{P.T.O}