The number of slip rings on a squirrel cage induction motor is usually
none
three
two
four
none
Star-delta starting of motors is not possible in case of
high speed motors
single phase motors
variable speed motors
low horse power motors
single phase motors
The term ‘cogging’ is associated with
induction motors
three phase transformers
compound generators
D.C. series motors
induction motors
The starting torque of a squirrel-cage induction motor is
slightly more than full-load torque
same as full-load torque
negligible
low
low
An induction motor with 1000 r.p.m. speed will have
8 poles
4 poles
6 poles
2 poles
6 poles
An induction motor is identical to
asynchronous motor
synchronous motor
D.C. series motor
D.C. compound motor
asynchronous motor
The torque developed in the cage induction motor with auto start is
K2 x torque with direct switching
K x torque with direct switching
k/torque with direct switching
k2/torque with direct switching
K2 x torque with direct switching
Rotor rheostat control method of speed control is used for
none of the above
slip ring induction motors only
squirrel-cage induction motors only
both and (2)
slip ring induction motors only
It is advisable to avoid line-starting of induction motor and use starter because
motor takes five to seven times its full load current
it will pick-up very high speed and may go out of step
it will run in reverse direction
starting torque is very high
motor takes five to seven times its full load current
The ‘crawling” in an induction motor is caused by
improper design of machine
low voltage supply
high loads
harmonics developed in the motor
harmonics developed in the motor
पोस्ट अच्छी लगी हो तो प्लीज नीचे दिए गए लिंक पर क्लिक कर शेयर जरुर करें
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