Prob. 12. A D.C. series motor runs at 500 r.p.m. drawing 40 A from 600supply. Determine the value of the external resistance to be added in serieswith the armature for the motor to run at 450 r.p.m. The load torque vwriesas the square of the speed. Assume linear magnetisation and take armatureresistance as 0.3 ohm and series field resistance is 0.2 ohm.

Answered: Image /qna-images/answer/c1e062f8-eca1-4a70-9672-f6fc4ce4b1bd.jpg

Prob. 12. A D.C. series motor runs at 500 r.p.m. drawing 40 A from 600 V supply. Determine the value of the external resistance to be added in serivr with the armature for the moter to run at 450 r.p.m. The load torque varies as the square of the speed. Assume linear magnetisation and take armature resistance as 0.3 ohm and series field resistance is 0.2 ohm.

Prob. 12. A D.C. series motor runs at 500 r.p.m. drawing 40 A from 600 V supply. Determine the value of the external resistance to be added in serivr with the armature for the moter to run at 450 r.p.m. The load torque varies as the square of the speed. Assume linear magnetisation and take armature resistance as 0.3 ohm and series field resistance is 0.2 ohm.

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 A permanent magnet DC motor has an armature resistance supplied by a 75-V DC Source, 1.4 S2. When it n svy t no-load speed d 2200 pm and draws 1.7 A. a) what 6.) What is the rotational'loss ? TS the output power (in hp) when it is operated at from 1800 rpm a 70-V DC source 7
I need the answer as soon as possible
A 200 V D.C. shunt motor takes 20 A at rated voltage and runs at 1000 r.p.m. Itsarmature resistance is 0.1 ohm. Calculate the value of additional resistance requiredin the armature circuit to reduced the speed to 800 r.p.m when the load torque isindependent of the speed.Ignore the field current. (Ans.1.98 ohm)
(c) What are the principle characteristics of DC series motor and DC compound motor, and what are its uses?
I need the answer as soon as possible
A 4 pole10V, DC shunt motor operates on a load current 10A, having wave connected armature with 200 conductors. The flux per Pole is 25 m Wb. Resistance of shunt field winding is 1 ohm and resistance of the armature is 0.15 ohm. a) what would be the back emf?
A 230 V DC Shunt motor runs at 700 r.p.m. and takes armature current of 40 A. Find resistance to be added to the field circult to increase speed to 1200 r.p.m. at an armature current of 60 A. Assume flux proportional to field current. Armature resistance = 0.12 n and field winding resistance is 115h
On full-load a 300 V series motor takes 90A and runs at 15 rev/s. The armature resistance is 0.1 ohm and the series winding resistance is 50 m.Determine the speed when developing full load torque but with a 0.2 ohm diverter in parallel with the field winding. (Assume that the flux is proportional to the field current.
Q2) Determine the back e.m.f at this load of series motor has a series field resistance of (0.301 2) and an armature resistance of (0.1892).It is connected to a (220 V) supply and at a particular load runs at (1500 r.p.m) when drawing (16.2 A) from the supply, if that this cases a three times of flux. Calculate the speed of motor when the load is changed such that the current is increased to (32.23 A).
Q15. A series-wound motor is connected to a d.c. supply and develops full-load torque when the current is 30 A and speed is 1000 rev/min. If the flux per pole is proportional to the current flowing, find the current and speed at half full- load torque, when connected to the same supply.
A 500 V DC shunt motor takes 4 A at no-load. The shunt field winding resistance and the armature winding resistance are 250 and 0.2 respectively. Find the efficiency when the motor draws a current of 10 A at full load.
Q1. (A)- A series DC motor runs at 600 r.p.m drawing a current of 52A when connected to 220 V supply. The total resistance of the machine is 0.14 2. Calculate the value of the external resistance to be connected in series with the motor circuit to reduce its speed to 400 r.p.m. Assume the load torque is decreased to half of the previous value. Consider the field flux is proportional to armature current.