Related Questions

In squirrel cage induction motors, the rotor slots are usually given slight skew in order to
A Reduce windage losses
B Reduce eddy currents
C Reduce accumulation of dirt and dust
D Reduce magnetic hum
When the equivalent circuit diagram of doouble squirrelcage induction motor is constructed the two cages can be considered
A in series
B in parallel
C in series-parallel
D in parallel with stator
In an induction motor the relationship between stator slots and rotor slots is that
A Stator slots are equal to rotor slots
B Stator slots are exact multiple of rotor slots
C Stator slots are not exact multiple of rotor slots
D None of the above
The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it
A improves the efficiency
B helps the rotor teeth to remain under the stator teeth
C helps in reducing the tendency of the rotor teeth to remain under the stator teeth
D improves the power factor
A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is
A Slop speed operation
B High starting torque
C Low windage losses
D All of the above
While starting a synchronous motor by induction motor action, field winding is usually
A connected to D.C. supply
B short-circuited by low resistance
C kept open-circuited
D none of the above
Great earthquakes usually begin with slight tremors but ---- take the form of one of more violent shocks, and end in vibrations of gradually diminishing force a called aftershocks.
A desperately
B rapidly
C abudantly
D considerately
Insertion of resistance in the rotor of an induction motor to develop a given torque
A Decreases the rotor current
B Increases the rotor current
C Rotor current becomes zero
D Rotor current remains same
The torque of a rotor in an induction motor under running condition is maximum
A At the unit value of slip
B At the zero value of slip
C At the value of the slip which makes rotor reactance per phase equal to the resistance per phase
D At the value of the slip which makes the rotor reactance half of the rotor
What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero?
A The slip of the motor will be 5%
B The rotor will not run
C The rotor will run at very high speed
D The torque produced will be very large

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