Electrical Machines solved Questions|Gate Questions Electrical Machines

In this post, Electrical Machines MCQ questions are given which asked for GATE Electrical exam.

The slip of an induction motor normally does not depend on

(A) rotor speed (B) synchronous speed

(C) shaft torque (D) core-loss component

A 220 V, 15 kW, 100 rpm shunt motor with armature resistance of 0.25 ฮฉ,

has a rated line current of 68 A and a rated field current of 2.2 A. The

change in field flux required to obtain a speed of 1600 rpm while drawing a

line current of 52.8 A and a field current of 1.8 A is

(A) 18.18% increase (B) 18.18% decrease

(C) 36.36% increase (D) 36.36% decrease

The locked rotor current in a 3-phase, star connected 15 kW, 4 pole, 230 V, 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 V, 57 Hz supply is

(A) 58.5 A (B) 45.0 A

(C) 42.7 A (D) 55.6 A

A single phase 10 kVA, 50 Hz transformer with 1 kV primary winding draws 0.5 A and 55W, at rated voltage and frequency, on no load. A second transformer has a core with all its linear dimensions 2 times the corresponding dimensions of the first transformer. The core material and lamination thickness are the same in both transformer. The primary winding of both the transformers have the save number of turns. If a rate voltage of 2 kV at 50 Hz is applied to the primary of the second transformer, then the no load current and power, respectively, are

(A) 0.7 A, 77.8 A (B) 0.7 A, 155.6W

(C) 1A, 110W (D) 1A, 220W

A 4 point starter is used to start and control the speed of a

(A) dc shunt motor with armature resistance control

(B) dc shunt motor with field weakening control

(C) dc series motor

(D) dc compound motor

                                                                   please comment your answers below

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Electrical Machines Best Books

Sl no.Book
Title
AuthorBuy Link
1Textbook Of Electrical Technology :
Ac And Dc Machines (volume – 2)
B L Theraja, AK Therajacheck price
2Theory & Performance of Electrical MachinesJ.B. Guptacheck price
3Electrical Machinesby V.K Mehta, Rohit Mehtacheck price
4Electric MachinesPS Bimbhracheck price
5Electrical MachinesS.K. Bhattacharyacheck price

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