• 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.

Answered: Image /qna-images/answer/cc1eea69-47fa-43ef-8ff6-586aa10f89e9.jpg

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

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
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.
In an Induction motor, if the load is decreased, what happens to the power factor?Select one:a. Power factor increasesb. Power factor becomes instablec. Power factor has no relation with loadd. Power factor decreases
A 220V dc shunt motor takes 4A at no load and runs at 700 rpm. Ra = 0.60 ohm and Rsh = 110 ohms. What is the efficiency of the motor when the motor input is 8800 W? a. 81.67% b. 80.2% c. 82.05% d. 79.44%
200 +21. If maximum torque of an induction motor is kg-m at a slip of 12%, the torque at 6% slip would be...... kg-m. 1 (a) 100 (b) 160 (c) 50 (d) 40 B, 1993)
An induction motor having full load torque of 60 Nm when delta-connected develops a starting torque of 120 Nm. For the same supply voltage, if motor is changed to star -connection, then starting torque developed will be Nm.
In a three-phase induction motor the maximum torque occurs at 20% slip and the equivalent resistance of the secondary is 0.04Ω per phase. Find the equivalent load resistance and the load voltage and the load current. Output power is 20 kW.
Please try to explain the steps. Question below.
A 3-phase induction motor has a starting torque 100% and a maximum torque of 200% of the full load toque. Find the slip at maximum torque. Answer: 26.8%
Q3 A 50 Hz split-phase induction motor has a resistance of 50 and an inductive reactance of 200 in the main winding as well as starting winding. Determine the value of resistance and capacitance to be added in series with the starting winding to send the same current in each winding with a phase difference of 90°. Ans[ 14.99 Ω, 127.5μF]
L-1). The 3-phase wound-rotor induction motor has .... . a) high starting torque b) low starting current c) both "a" and "b" d) neither "a" nor "b" L-2). The 3-phase wound-rotor induction.........a) motor has a wire wound rotor b) motor's rotor can be connected to an external resistive load by way of slip rings and brushes c) motor requires more maintenance than the 3-phase squirrel-cage induction motor d) all of the above L-3). The 3-phase wound-rotor induction motor's rotor circuit's resistance should be adjusted so it is__________ during starting. a) low b) high c) either "a" or "b" d) neither "a" nor "b" L-4). Will a 3-phase wound-rotor induction motor start with no external circuit connected to its rotor leads? a) yes b) no

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