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Which of the following component is usually fabricated out of silicon steel ?Which of the following component is usually fabricated out of silicon steel ?
The answer is:
C. Statorcore


The frame of an induction motor is usually made ofThe frame of an induction motor is usually made of
The answer is:
B. cast iron


The shaft of an induction motor is made ofThe shaft of an induction motor is made of
The answer is:
A. stiff


The shaft of an induction motor is made ofThe shaft of an induction motor is made of
The answer is:
C. carbon steel


In an induction motor, noload the slip is generallyIn an induction motor, noload the slip is generally
The answer is:
A. less than 1%


In medium sized induction motors, the slip is generally aroundIn medium sized induction motors, the slip is generally around
The answer is:
C. 4%


In squirrel cage induction motors, the rotor slots are usually given slight skew in ordertoIn squirrel cage induction motors, the rotor slots are usually given slight skew in orderto
The answer is:
D. reduce magnetic hum


In case the air gap in an induction motor is increasedIn case the air gap in an induction motor is increased
The answer is:
B. the power factor will decrease


Slip rings are usually made ofSlip rings are usually made of
The answer is:
C. phospor bronze


A 3phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor e.m.f. willbeA 3phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor e.m.f. willbe
The answer is:
C. 2 Hz


In Ns is the synchronous speed and s the slip, then actual running speed of aninduction motor will beIn Ns is the synchronous speed and s the slip, then actual running speed of aninduction motor will be
The answer is:
C. (ls)Ns


The efficiency of an induction motor can be expected to be nearlyThe efficiency of an induction motor can be expected to be nearly
The answer is:
B. 80 to 90%


The number of slip rings on a squirrel cage induction motor is usuallyThe number of slip rings on a squirrel cage induction motor is usually
The answer is:
D. none


The starting torque of a squirrelcage induction motor isThe starting torque of a squirrelcage induction motor is
The answer is:
A. low


A double squirrelcage induction motor hasA double squirrelcage induction motor has
The answer is:
C. two parallel windings in rotor


Stardelta starting of motors is not possible in case ofStardelta starting of motors is not possible in case of
The answer is:
A. single phase motors


The term 'cogging' is associated withThe term 'cogging' is associated with
The answer is:
D. induction motors


In case of the induction motors the torque isIn case of the induction motors the torque is
The answer is:
D. directly proportional to slip


An induction motor with 1000 r.p.m. speed will haveAn induction motor with 1000 r.p.m. speed will have
The answer is:
B. 6 poles


The good power factor of an induction motor can be achieved if the average fluxdensity in the air gap isThe good power factor of an induction motor can be achieved if the average fluxdensity in the air gap is
The answer is:
B. small

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