69.

71.

79.

74.

75,

76.

What will be the load power factor, if one waltmeter read positive and the other zero in a
two wattmeter method for power measurement ?

(ಗಿ) पणा (18) 2616 (ಲ) 05 lag (D) 05 lead

A dynamometer moving coil instrument can measure :
(ಗಿ) ac only (B) d.c. only
(C) both acand १.६. (D) only pulsating quantities

Which of the following bridge rectifiers has highest harmonic content in output voltage ?
(A) 1-phase half wave (B) 1-phase full wave
(C) 3-phase half wave (D) 3-phase full wave

The rotor copper loss for a 4 pole 3-phase 50 Hz induction motor running at 1495 rpm is
50 W. Its rotor input is :

(A) 250 W © 15 kw ട്ര 50% (D) 100 W

The electrical representation of the variable mechanical load of a 3-phase induction motor is
the resistance given by :

വി © ‏بحمو‎ ಇ (1... [4-1]

If V is the voltage applied to the stator of an induction motor, the electrical torque Te is
proportional to :

@ v ® 2v © v @ ४१

The rotor slots of squirrel cage induction motor are given a slight skew in order to :
(^) reduce eddy currents (8) reduce magnetic hum
(9) reduce windage loss (D) reduce accumulation of dirt and dust

The speed of a 3-phase, 4 pole, 440 V 50 Hz induction motor is 1440 rpm. What is the
frequency of rotor emf ?

(A) 200 Hz (B) 50 Hz (ര) 21% (D) 48 Hz

The cogging in an induction motor is caused by : ”

(8) high loads (8) harmenics developed 17 the motor
(ಲ) low voltage supply (D) _none of the above
n 117/2014

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