| 1. | In case of a shunt motor if the supply voltage is increased by 10%, which of the following will decrease ? | |
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full load current
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full load speed
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starting torque
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none of the above
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Report Question| 2. | Which of the following methods of braking is used in rolling mills ? | |
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Dynamic braking
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Plugging
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Regenerative braking
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Mechanical brakes
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| 3. | For which application a D.C. motor is preferred over an AC. motor ? | |
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High speed operation
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Low speed operation
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Fixed speed operation
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Variable speed operation
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| 4. | Which motor should not be started on no-load ? | |
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Series motor
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Shunt motor
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Cumulatively compounded motor
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Differentially compounded motor
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| 5. | Which of the following can be used for controlling the speed of a D.C. motor ? | |
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Thermistor
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Transistor
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Thyratron
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Thyristor
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| 6. | In a D.C. shunt motor, speed is ? | |
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independent of armature current
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directly proportional to the armature current
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proportional to the square of the current
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inversely proportional to the armature current
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| 7. | The hysteresis loss in a D.C. machine least depends on ? | |
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Frequency of magnetic reversals
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Maximum value of flux density
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Volume and grade of iron
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Rate of flow of ventilating air
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| 8. | A brake test on D.C. motors is usually restricted to ? | |
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small horse power motors
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variable speed motors
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high speed motors
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open frame type motors
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| 9. | In hazardous area of gassy mines, material transportation is done by vehicles powered by ? | |
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A.C. mains
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D.C. mains
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I.C. Engines
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batteries
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| 10. | If the supply voltage for a D.C. motor is increased, which of the following will decrease ? | |
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Starting torque
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Operating speed
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Full-load current
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All of the above
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