• A 120-V, 2400-rpm shunt motor has an armatureresistance of 0.4 2 and a shunt field resistance of 160 2.The motor operates at its rated speed at full load andtakes 14.75 A. The no-load current is 2 A. An externalresistance of 80 Q is inserted in series with the shuntfield winding instead of the armature circuit, determine(a) the motor speed, (2907 rpm)(b) the power loss in the external resistance, and (20 W)(c) the efficiency. (84.8%)• Assume that the flux is proportional to the square root ofthe field-winding current and the motor develops thesame torque.

# Given Data:- Voltage V=120V - Rated speed N=2400rpm- Armature resistance Ra=0.4Ω - Shunt field…

Answered: • A 120-V, 2400-rpm shunt motor has an…

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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An 8 pole, 50 Hz slip ring induction motor runs at a slip of 2.67% on full load. The rotor resistance per phase of the winding is 0.2 ohm. What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17.33% such that the torque remains same in both the cases. (Ans: 1.1 ohm)
Design a DC motor circuit to drive A fan-type load with a torque equation equal to: TL=1.34×10−7ω2TL=1.34×10−7ω2 N.m The fan speed range is from 500 to 1200 rpm. To achieve the required operation, the armature voltage of the motor is adjusted by a single-phase, full-wave, ac/dc converter. The input voltage and frequency to the converter are 480 V (rms) and 50 Hz. choose the motor type, show the motor rating, αα range, Supply voltage, and frequency, and any required other information Modify the design to automatically adjust the voltage drive the load within the specified speed range. show the control variable, controller type, connection, and controller weights.
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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
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