7) The wound-rotor induction motors are rarely used, and it is not so common in industry applications. 8) For a 50 Hz, 8 pole induction motor, the synchronous speed of this motor is 650 r/m. 9) A 480-V, 50-Hz three-phase induction motor is drawing 40 A at 0.8 PF lagging, if the stator copper losses are 1800 W, and the core losses are 1050 W, then the air-gap power is 22500W.

7) The wound-rotor induction motors are rarely used, and it is not so common in industry applications. 8) For a 50 Hz, 8 pole induction motor, the synchronous speed of this motor is 650 r/m. 9) A 480-V, 50-Hz three-phase induction motor is drawing 40 A at 0.8 PF lagging, if the stator copper losses are 1800 W, and the core losses are 1050 W, then the air-gap power is 22500W.

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter35: Harmonics 916

Section: Chapter Questions

Problem 3RQ: Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction...

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Similar questions

Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction motor? Explain your answer.
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
2. Describe the Torque-Slip characteristics of a three phase induction motor.
Write a summary ( point) about equivalent cricuit of three phase induction motor .
7- A 6-pole, 50-Hz, 3-0 induction motor is running at 950 rpm and has rotor Cu loss of 6 kW. Its rotor input is......kW (a) 120 (b) 60 (c) 6.3 (d) 66 8- The number of slip rings on a squirrel cage induction motor is usually (a)Two (b) Three (c) Four (d) None
If a 4-pole induction motor has a synchro- nous speed of 1500 r.p.m., then, supply fre- quency is (1) 50 Hz 60 Hz (iii) (ii) 25 Hz (iv) none of the above
Discuss the following statements briefly 1. Adding auxiliary winding in single phase induction motors. The starting capacitor of a capacitor start capacitor run induction motor is 100 µF while the running capacitor is 14 µF.
Explain in detail the Starting of Induction Motors
At standstill condition , the slip of induction motor is 1. Select one: O True O False
1.why the slip of induction motor is never zero, 2.what happens if the slip of induction motor is one, 3.what is the value of the slip for an induction motor at on load and full load
Draw the typical speed-torque characteristic of the induction motor and expain it.
The use of a series capacitor with the auxiliary windings of a single-phase induction motor permits: * The obtaintion a 90-degrees phase angle between currents in the main and auxiliary windings. The garantee a relatively high starting torque all above