Consequence of motor effect isA. electromagnetic induction B. current C. voltage D. e.m.f

 Consequence of motor effect isA. electromagnetic induction

B. current

C. voltage

D. e.m.f
by

1 Answer

Answer :

electromagnetic induction


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Related questions

A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is delivering rated output, the slip is found to be 0.05. The speed of the rotor m.m.f. relative to the rotor structure is (A) 1500 r.p.m. (B) 1425 r.p.m. (C) 25 r.p.m. (D) 75 r.p.m.

Description : A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is delivering rated output, the slip is found to be 0.05. The speed of the rotor m.m.f. relative to the rotor structure is (A) 1500 r.p.m. (B) 1425 r.p.m. (C) 25 r.p.m. (D) 75 r.p.m.

Last Answer : (D) 75 r.p.m.

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In Hall effect, voltage across probe is known as A. hall voltage B. e.m.f C. potential difference D. hall potential

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The left hand rule correlates to (a) current, induced e.m.f. and direction of force on a conductor (b) magnetic field, electric field and direction of force on a conductor (c) self induction, mutual induction and direction of force on a conductor (d) current, magnetic field and direction of force on a conductor

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If a student drops a stone from a cliff of height 30 m and the time it takes to reach the ground is 2.6 s, then the acceleration due to gravity isA. 9 m s-2B. 10 m s-2C. 4 m s-2D. 8.8 m s-2

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: Moving a coil in and out of magnetic field induces A. force B. potential difference C. e.m.f D. voltage

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The following air gap readings were obtained from a horizontally mounted, bilge pump, induction motor, equipped with sleeve bearings: FWD END-AFT END, Top .045 - .049, Right Side .045 - .047, Left Side .045 - .047, Bottom .045 - .041 Which of the f A. both the aft and foward bearings should be replaced. B. Shims should be removed from the aft bearing. C. The forward bearing should be lowered. D. The aft bearing should be lowered.

Description : The following air gap readings were obtained from a horizontally mounted, bilge pump, induction motor, equipped with sleeve bearings: FWD END-AFT END, Top .045 - .049, Right Side .045 - .047, Left ... the aft bearing. C. The forward bearing should be lowered. D. The aft bearing should be lowered.

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Rotor shaft of a large electric motor supported between short bearings at both ends shows a deflection of 1.8 mm in middle of motor. Assuming rotor to be perfectly balanced and supported at knife edges at both ends, likely critical speed (rpm) of shaft isA 350 B 4430 C 705 D 2810

Description : Rotor shaft of a large electric motor supported between short bearings at both ends shows a deflection of 1.8 mm in middle of motor. Assuming rotor to be perfectly balanced and supported at knife edges at both ends, likely critical speed (rpm) of shaft isA 350 B 4430 C 705 D 2810

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A split-phase induction squirrel-cage motor will not come up to speed, even though the rated voltage, rated frequency, and rated load are applied. The suspected trouble could be due to _____________. A. a faulty centrifugal switch B. broken rotor bars C. worn bearings D. all of the above

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The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. changing the RPM of the rotor flux C. changing the phase sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

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Under normal conditions, the speed of a two-speed squirrel cage induction motor is changed by varying the ____________. A. frequency of the applied voltage B. resistance in the rotor circuit C. number of field poles D. amplitude of the applied voltage

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A characteristic of a wound-rotor induction motor, with a high resistance rotor winding, is _____________. A. low starting torque B. high starting torque C. high speed D. low starting voltage

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The variable resistance placed in the rotor circuit of a wound-rotor induction motor provides for __________. A. speed control B. frequency control C. voltage control D. use as a split-phase motor

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Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for 'across-the-line starting' C. provide a backup means of voltage regulation for emergency starting D. allow the voltage to be either stepped up or down, depending on the application, to ensure full torque

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What are the effects of unbalanced voltage on induction motor?

Description : What are the effects of unbalanced voltage on induction motor?

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Explain speed control method of 3 phase induction motor by the following methods: (1) Pole changing (2) Rotor resistance control (3) Stator voltage

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In a 3-phase voltage source inverter used for speed control of induction motor, anti-parallel diodes are used

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A 3-phase induction motor is driving a constant torque load at rated voltage and frequency. If both voltage

Description : A 3-phase induction motor is driving a constant torque load at rated voltage and frequency. If both voltage and frequency are halved, following statements relate to the new condition if stator resistance, leakage reactance and core loss are ... (A) All (B) 1, 2 and 3 (C) 2, 3 and 4 (D) 1 and 4

Last Answer : A 3-phase induction motor is driving a constant torque load at rated voltage and frequency. If both voltage and frequency are halved, following statements relate to the new condition if stator resistance, leakage reactance and core loss are ... A) All (B) 1, 2 and 3 (C) 2, 3 and 4 (D) 1 and 4

No-load test on a 3-phase induction motor was conducted at different supply voltage and a plot of input

Description : No-load test on a 3-phase induction motor was conducted at different supply voltage and a plot of input power versus voltage was drawn. This curve was extrapolated to intersect the y-axis. The intersection point ... ) Core loss (B) Stator copper loss (C) Stray load loss (D) Friction and windage loss

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A three-phase cage induction motor is started by direct-on-line (DOL) switching at the rated voltage. If the

Description : A three-phase cage induction motor is started by direct-on-line (DOL) switching at the rated voltage. If the starting current drawn is 6 times the full load current, and the full load slip is 4%, then ratio of the ... load torque is approximately equal to (A) 0.24 (B) 1.44 (C) 2.40 (D) 6.00

Last Answer : A three-phase cage induction motor is started by direct-on-line (DOL) switching at the rated voltage. If the starting current drawn is 6 times the full load current, and the full load slip is 4%, then ratio of the starting developed torque to the full load torque is approximately equal to 1.44

When the supply voltage to an induction motor is reduced by 10%, the maximum torque will decrease by

Description : When the supply voltage to an induction motor is reduced by 10%, the maximum torque will decrease by about  A) 5% B) 10% C) 20% D) 40%

Last Answer : When the supply voltage to an induction motor is reduced by 10%, the maximum torque will decrease by about 20%

A change of 4% in the supply voltage to an induction motor will produce a change of approximately

Description : A change of 4% in the supply voltage to an induction motor will produce a change of approximately

Last Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control

Description : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

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In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then

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A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage...

Description : A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage drops to 90% of the rated value, % increase in motor copper losses  (a) 23% (b) -18% (c) 123% (d) None of these

Last Answer : A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage drops to 90% of the rated value, % increase in motor copper losses (a) 23% (b) -18% (c) 123% (d) None of these

A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is ...

Description : A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is delivering rated output, the slip is found to be 0.05. The speed of the rotor m.m.f. relative to the rotor structure is: (A) 1500 r.p.m. (B) 1425 r.p.m. (C) 25 r.p.m. (D) 75 r.p.m

Last Answer : A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is delivering rated output, the slip is found to be 0.05. The speed of the rotor m.m.f. relative to the rotor structure is: 75 r.p.m

Reduction in supply voltage by 10% will change the torque of an induction motor by

Description : Reduction in supply voltage by 10% will change the torque of an induction motor by   (a) 38% (b) 19% (c) 9.5% (d) No change 

Last Answer : Answer is (b)

Stator Voltage Control of three phase induction motor

Description : Stator Voltage Control of three phase induction motor

Last Answer : Stator Voltage Control of three phase induction motor

Sum of e.m.f around any loop equals A. sum of current B. sum of potential difference C. sum of resistances D. sum of charges passing through it per second

Description : Sum of e.m.f around any loop equals A. sum of current B. sum of potential difference C. sum of resistances D. sum of charges passing through it per second

Last Answer : sum of potential difference

A voltmeter arranged across the power supply measures A. potential difference B. e.m.f C. current D. resistance

Description : A voltmeter arranged across the power supply measures A. potential difference B. e.m.f C. current D. resistance

Last Answer : e.m.f