improves the efficiency
helps the rotor teeth to remain under the stator teeth
helps in reducing the tendency of the rotor teeth to remain under the stator teeth
improves the power factor
Answer is Right!
Answer is Wrong!
Single phase induction motors
82. Which of the following single-phase motors is suitable for timing and control purposes ?
Reluctance motor
Series motor
Repulsion motor
Universal motor
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Answer is Wrong!
83. The motor used on small lathes is usually
universal motor
D.
shunt motor C. single-phase capacitor run motor
3-phase synchronous motor
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Answer is Wrong!
84. Which of the following motors has two separate windings on the motor ?
Repulsion motor
Repulsion induction motor
Repulsion start induction run motor
None of the above
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Answer is Wrong!
Detailed SolutionWhich of the following motors has two separate windings on the motor ?
85. As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for
fans
blowers
sound equipment
mixer grinders
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86. Which of the following motors is used for unity power factor ?
Hysteresis motor
Schrage motor
Universal motor
Reluctance motor
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Answer is Wrong!
Detailed SolutionWhich of the following motors is used for unity power factor ?
87. In a shaded pole motor, the shading coil usually consist of
a single turn of heavy wire which is in parallel with running winding
a single turn of heavy copper wire which is short-circuited and carries only induced current
a multilayer fine gauge copper wire in parallel with running winding
none of the above
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Answer is Wrong!
Detailed SolutionIn a shaded pole motor, the shading coil usually consist of
88. In repulsion motor, zero torque is developed when
brush axis is 45° electrical to field axis
brush axis coincides with the field axis
brush axis is 90° electrical to field axis
both (B) and (C)
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Detailed SolutionIn repulsion motor, zero torque is developed when
89. Which of the following statements regarding single-phase induction motoris correct ?
It requires only one winding
It can rotate in one direction only
It is self-starting
It is not self-starting
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Answer is Wrong!
90. Torque developed by a single phase induction motor at starting is
pulsating
uniform
none of the above
nil
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Answer is Wrong!
Detailed SolutionTorque developed by a single phase induction motor at starting is