| 1. | A D.C. shunt motor is rotating in clockwise direction as viewed from one end. The polarity of connection of the armature and field winding are reversed simultaneously. The motor will ? | |
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rotate in clockwise direction
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rotate in anti-clockwise direction
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will not rotate at all
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gain excessively high speed
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Report Question| 2. | The armature shaft of a D.C. motor must be able to withstand ? | |
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any unbalanced magnetic pull on the armature core
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twisting strains due to transmission of torque
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bending moment due to the weight of the armature and commutator
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all of the above
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| 3. | Which losses can be determined by performing the retardation test ? | |
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Friction losses
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Eddy current losses
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Stray losses
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Copper losses
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| 4. | Speed control by varying the armature circuit resistance, in a D.C. motor, provides a ? | |
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constant torque drive
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variable torque drive
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constant power drive
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variable power drive
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| 5. | A face plate starter is employed for starting ? | |
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induction motor
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universal motor
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synchronous motor
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d.c. series motor
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| 6. | The operation of electric generators and motors depend on the interaction between magnetic field and ? | |
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copper conductors
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electric field
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electric current
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commutator
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| 7. | If the field of a D.C. shunt motor gets opened while motor is running ? | |
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the speed of motor will be reduced
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the armature current will reduce
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the motor will attain dangerously high speed
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the motor will continue to run at constant speed
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| 8. | No-load speed of which of the following motor will be highest ? | |
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Shunt motor
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Series motor
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Cumulative compound motor
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Differentiate compound motor
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| 9. | If a D.C. motor designed for 40ºC ambient temperature is to be used for 50ºC ambient temperature, then the motor ? | |
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of lower H.P. should be selected
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of higher H.P. should be selected
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can be used for 50ºC ambient temperature also
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to be derated by a factor recommended by manufacturer and select the next higher H.P. motor
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| 10. | All motors, basically, operate on the principle of either repulsion or ? | |
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induction
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semi-conduction
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capacitance
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electro-magnetism
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