24.

25.

26.

27.

28.

29.

30.

The equivalent circuit of a transformer has leakage reactances X,,X;and magnetizing
reactance Xm. The magnitude satisfy :

(0) >, >> ‏رلا << إلا‎ (3) >, << ¦ << +
(C) X,=X}>>X,, (0) >, = ¦ <<

The winding used ina 3-phase shell type transformer is type:
(^) Circular ൯) Cylindrical
(C) Sandwich (D) Rectangular

In a power transformer:
(^) The primary winding is always wound with many turn of thin wire
(B) Secondary winding is always wound with lesser number of turns of thin wire
(C) Low voltage winding is always wound with lesser number of turns of thick wire

(D) High voltage winding is always wound with large number of turns of thicker wire

Which one of the following is the primary reason for placing field on rotor in an alternator?
(A) Small power in the field circuit
(B) Insulation of high voltage is made easy on stator than on rotor
(C) Large power in stator

(D) Large current in stator

Which of the following method is employed for starting a 3-phase synchronous motor?
(^) Star-delta starter
(B) Damper winding
(C) Resistance starter in the stator circuit

(D) Damper winding in conjunction with the star delta starter or an auto-transformer
starter

Which of the following material of slip ring in an induction machine?

(A) Carbon (B) Nickel
(C) Phosphor bronze (D) Manganese

A500 HP, 6 pole, 3-phase, 440 V, 50 Hz induction motor has a speed of 950 rpm on full load.
The full load slip and the number of cycles the rotor voltage makes per minute will be
respectively :

(A) 10% and 150 (B) 10% and 125
(C) 5%and 150 (D) 5% and 125

7 225/2023
[P.T.0.]