• A 120-V shunt motor has R₁ = 0.25 0 and Rfw = 802. The motor takes 4 A at a no-load speed of 1500rpm. If the motor is to develop a torque of 20 N-m ata speed of 2000 rpm, determine the externalresistance that must be added in series with the fieldwinding. (352)• If the rotational loss is proportional to the speed,determine the efficiency and the horsepower ratingof the motor at 2000 rpm.

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Answered: • A 120-V shunt motor has R₁ = 0.25 0…

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter32: Three-phase Motors

Section: Chapter Questions

Problem 6RQ: Name three factors that determine the torque produced by an induction motor.

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Similar questions

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The dc series motor has a linear torque- speed characteristics. O True O False
pole. 50-Hz. 3-ϕ induction motor has a full-load speed of 950 rpm. At half load its speed would be ..... rpm a) 475 b) 500 c) 975 d)1000
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6- Which of the following supply is given to the rotor winding of 3-Phase Induction Motor: a) DC Supply b) AC Supply c) No Supply d) Pulsating Supply 7- 3-Phase Induction Motor will have Starting Torque and Starting Current a) High, High b) Low, Low. c) High, Low d) Low, High 8- Which of the following method is used for controlling the speed of an induction motor: a) Changing number of stator poles b) Supply voltage control c) Frequency control d) All the options are correct 9- Which of the following method cannot be used for starting of 3-Phase Squirrel Induction Motor: a) Star-Delta Starting b) Line resistor startling c) transformer Starter d) Rotor Resistance Starting 10- The rotor of a stepper motor has no: a) windings b) commutator c) brushes d) all of the above
A 250 V series motor has an armature resistance of 0.2 ohm and a series-fieldresistance of 0.18 ohm. If the speed is 6oo RPM when the current is 32 amps.What will be the motor speed when the load is reduced so that the current is18 amps, under which condition the percent flux change is 50 % of the percentcurrent change.
A 230v DC series motor takes 30A when giving its rated output at 1400 rpm. It has a field resistance of 0,4 ohms, Calculate the value of the resistance (Ra) of the armature when Eb = 200V. Select the correct response: 0.2 ohms 0.6 ohms 0.8 ohms 0.4 ohms
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Q ...
2. A 2-pole, 50 Hz induction motor supplies 15 kW to a load at a speed of 2950 rpm. a. What is the motor's slip? b. What is the induced torque in the motor in N-m under these conditions? c. What will be the operating speed of the motor be if its torque is doubled? d. How much power will be supplied by the motor when the torque is doubled?

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