A 1200-V, 4-pole, de motor with 24 current paths, 200 coils and 50 turns per coil is rotating at 1000 rpm.Assume the total flux per pole is 0.02 Wb. and rotor circuit resistance is 1.8 Ohm.a) Find the voltage induced at its terminals.b) Find the current of the motor when it is connected to its rated voltage. Assume the brush voltagedrop is 28 V.c) Find the induced torque in the motor.d) Find the input electrical power supplied by the source.e) Find the electrical power delivered to the motor.f) If the core losses and mechanical losses are 3.2 kW, find the power delivered to the load.g) Find the motor efficiency (ignore the field losses). The de machine of Problem 1 is now rotating at 1200 rpm.a) Is it operating as a motor or generator? Find the induced voltage.b) Find the armature current assuming the same brush voltage drop.c) Find the induced torque.d) Find the machine efficiency assuming the same mechanical losses as Problem 1.

Q1DC Machine as a MotorPart 2: speed changes to 1200 rpm

Answered: A 1200-V, 4-pole, de motor with 24…

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...

See similar textbooks

Similar questions

A 220 V DC series motor runs drawing a current of 30 A from the supply. Armature and field circuit resistances are 0.4 and 0.1 respectively. The load torque varies as the square of the speed. The flux in the motor may be taken as being proportional to the armature current. To reduce the speed of the motor by 50% the resistance in ohms that should be added in series with the armature is
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
A 22 kW, 230 V Series DC motor runs at 750 rev/min at full load and draws 110 A from the supply. The resistance of the armature is 0.1250 and the series field 0.0250. Calculate the speed when the load is reduced such that the input current reduces to 56 A. Assume that the useful flux per pole at 110 A is 23.9 mWb and the flux for 56 A is be 15.5 mWb.
A 230 V dc series motor has an armature resistance of 0.2 ohm and field resistance of 0.1 ohm at rated voltage. The motor draws a line current of 40 amperes and runs at a speed of 1000 rpm. Find speed of the motor for line current of 20 A at 230 V. Assume that flux at 20 A line current is 60% of flux at 40 A line current.
(7) The only parts suffers from eddy currents in AC motors: a- The stator. b- The rotor. c- The stator and rotor. (8) The unit of torque is a- W (rad. s') b- Js -1 C- Nm
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?
16 A 4-pole dc series motor has wave connected winding with 600 conductors. When fed from 250 V dc source, the motor drives a load of 5 kW and takes 50 A with a flux per pole of 10 mWb. The torque developed is (Neglect losses).
26. A 4-pole, 50 Hz induction motor operates at 5% slip. The frequency of e.m.f. induced in the rotor will be .... (1) 25 Hz (iii) 2.5 Hz (ii) 50 Hz (iv) none of the above
A universal motor has armature circuit resistance of 15 ohm and inductanceof 0.3H. On being connected to a 220 V dc supply, it draws 1.5 A from themains and runs at 2000 rpm. Find the speed and power factor of the motor,when connected to a 230 V, 25 Hz supply and drawing the same armaturecurrent.
A 220-volt DC series motor is running at a speed of 800 r.p.m and draws 100 A. Total resistance of the armature and field is 0.1 ohm. 1. Calculate the speed when the torque is halved if the magnetic circuit is unsaturated. 2. If the torque was 250 N-m, calculate its new value when the current is doubled and the saturation is occurred
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

SEE MORE QUESTIONS

Recommended textbooks for you

Introductory Circuit Analysis (13th Edition)

Electrical Engineering

ISBN:

9780133923605

Author:

Robert L. Boylestad

Publisher:

PEARSON

Delmar's Standard Textbook Of Electricity

Electrical Engineering

ISBN:

9781337900348

Author:

Stephen L. Herman

Publisher:

Cengage Learning

Programmable Logic Controllers

Electrical Engineering

ISBN:

9780073373843

Author:

Frank D. Petruzella

Publisher:

McGraw-Hill Education

Introductory Circuit Analysis (13th Edition)

Electrical Engineering

ISBN:

9780133923605

Author:

Robert L. Boylestad

Publisher:

PEARSON

Delmar's Standard Textbook Of Electricity

Electrical Engineering

ISBN:

9781337900348

Author:

Stephen L. Herman

Publisher:

Cengage Learning

Programmable Logic Controllers

Electrical Engineering

ISBN:

9780073373843

Author:

Frank D. Petruzella

Publisher:

McGraw-Hill Education

Fundamentals of Electric Circuits

Electrical Engineering

ISBN:

9780078028229

Author:

Charles K Alexander, Matthew Sadiku

Publisher:

McGraw-Hill Education

Electric Circuits. (11th Edition)

Electrical Engineering

ISBN:

9780134746968

Author:

James W. Nilsson, Susan Riedel

Publisher:

PEARSON

Engineering Electromagnetics

Electrical Engineering

ISBN:

9780078028151

Author:

Hayt, William H. (william Hart), Jr, BUCK, John A.

Publisher:

Mcgraw-hill Education,

SEE MORE TEXTBOOKS