| 1. | The input impedance of an amplifier is ? | |
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Vin / (Iout - Iin)
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Vin / Iout
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Vin / Iin
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Vout / Iin
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Report Question| 2. | The speed regulation of a synchronous motor is always ? | |
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0.005
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0.01
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zero
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positive
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| 3. | In a synchronous motor, at constant loading condition, if the excitation is increased its power factor becomes ? | |
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more
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less
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constant
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no change
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| 4. | If excitation of a synchronous motor running with a constant load is decreased from its normal value, it leads to ? | |
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increase in both armature current and power factor angle
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increase in both armature current and power factor which is lagging
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increase in back e.m.f. but decrease in armature current
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increase in torque angle but decrease in back e.m.f.
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| 5. | At leading power factor the induced e.m.f. in a synchronous motor will be ? | |
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equal to the supply voltage
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less than the supply voltage
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more than the supply voltage
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None of these
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| 6. | A synchronous motor can be started by ? | |
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providing damper winding
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D.C. compound motor
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pony motor
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any of the options
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| 7. | In a synchronous motor, the torque angle is the angle between ? | |
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magnetizing current and back e.m.f.
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the rotating stator flux and rotor poles
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the supply voltage and the back e.m.f.
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None of these
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| 8. | Which of the following statement is TRUE ? | |
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The resistivity of a conductor does not depend on alloying of conductor material.
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The resistivity of a conductor does not depend on the temperature.
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The resistivity of a conductor does not depend on the length of the conductor.
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The resistivity of a conductor does not depend on the mechanical stress on the conductor.
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| 9. | Which of the following is the correct expression for the capacitance ? | |
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C= Q/V
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C= Q-V
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C= QV
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C= V/Q
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| 10. | In parallel combination of capacitances, the equivalent capacitance is ? | |
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equal to the largest capacitance of the combination
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lower than the largest capacitance of the combination
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lower than the smallest capacitance of the combination
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greater than the largest capacitance of the combination
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