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1) A hysteresis motor works on the principle of__________? a. hysteresis loss b. magnetisation of rotor c. eddy current loss d. electromagnetic induction
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2) Which of the following motor will give the highest starting torque ? a. D.C. shunt motor b. Schrage motor c. Repulsion start and induction run motor d. Universal motor
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3) The power factor of a single-phase induction motor is usually? a. lagging b. always leading c. unity d. unity to 0.8 leading
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4) A shaded pole motor can be used for_____________? a. toys b. hair dryers c. circulators d. any of the above
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5) In a capacitor start single-phase motor, when capacitor is replaced by a resistance____________? a. torque will increase b. the motor will consume less power c. motor will run in reverse direction d. motor will continue to run in same direction
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6) Short-circuiter is used in_____________? a. repulsion induction motor b. repulsion motor c. repulsion start induction run motor d. none of the above
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7) The range of efficiency for shaded pole motors is______________? a. 95% to 99% b. 80% to 90% c. 50% to 75% d. 5% to 35%
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8) Burning out of winding is due to___________? a. short circuited capacitor b. capacitor value hiving changed c. open circuiting of capacitor d. none of the above
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9) Direction of rotation of a split phase motor can be reversed by reversing the connection of__________? a. running winding only b. starting winding only c. either A. or (b) d. both A. and (b)
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10) Which of the following motors is inherently self starting ? a. Split motor b. Shaded-pole motor c. Reluctance motor d. None of these
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11) The direction of rotation of an hysteresis motor is determined by____________? a. interchanging the supply leads b. position of shaded pole with respect to main pole c. retentivity of the rotor material d. none of these
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12) A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will______________? a. start and then stop b. start and run slowly c. start and run at rated speed d. not start at all
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13) Which of the following motors is used in mixies ? a. Repulsion motor b. Reluctance motor c. Hysteresis motor d. Universal motor
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14) In a single phase motor the centrifugal switch____________? a. disconnects auxiliary winding of the motor b. disconnects main winding of the motor c. reconnects the main winding the motor d. reconnects the main winding the motor
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15) The running winding of a single phase motor on testing with meggar is found to be ground. Most probable location of the ground will be___________? a. at the end connections b. at the end terminals c. anywhere on the winding inside a slot d. at the slot edge where coil enters or comes out of the slot
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16) The value of starting capacitor of a fractional horse power motor will be__________? a. 100 uF b. 200 uF c. 300 uF d. 400 uF
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17) In repulsion motor direction of rotation of motor____________? a. is opposite to that of brush shift b. is the same as that of brush shift c. is independent of brush shift
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18) A centrifugal switch is used to dis- connect ‘starting winding when motor has___________? a. run for about 1 minute b. run for about 5 minutes c. picked up about 50 to 70 per cent of rated speed d. picked up about 10 to 25 per cent of rated speed
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19) In a shaded pole single-phase motor, the revolving field is produced by the use of_________? a. inductor b. capacitor c. resistor d. shading coils
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20) If a particular application needs high speed and high starting torque, then which of the following motor will be preferred ? a. Universal motor b. Shaded pole type motor c. Capacitor start motor d. Capacitor start and run motor
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