Universal Motor Problems8. A universal motor has a total resistance of 30 and a total inductanceof 0.5 H. When connected to a 250 V dc supply and loaded to 0.8 A, itruns at 2000 rpm. Determine (a) the speed in rpm, (b) developed torque,and (c) power factor when connected to 250 V, 50 Hz ac supply andloaded to take same amount of current.9. For the universal motor of Problem 8, if the rotational losses isnegligible, find the motor efficiency for both the dc and ac supply.10. For the universal motor of Problem 8 what is the motor speed range if anexternal rheostat R is connected in series with the motor as shown inFigure 2-11 and has a resistance range 0-100 . Solve for both the dcand ac supply.24

Answered: Image /qna-images/answer/00a93cc8-d3d1-484e-ba4b-b96b18190ec5.jpg

8. A universal motor has a total resistance of 30 and a total inductance of 0.5 H. When connected to a 250 V dc supply and loaded to 0.8 A, it runs at 2000 rpm. Determine (a) the speed in rpm, (b) developed torque, and (c) power factor when connected to 250 V, 50 Hz ac supply and loaded to take same amount of current.

8. A universal motor has a total resistance of 30 and a total inductance of 0.5 H. When connected to a 250 V dc supply and loaded to 0.8 A, it runs at 2000 rpm. Determine (a) the speed in rpm, (b) developed torque, and (c) power factor when connected to 250 V, 50 Hz ac supply and loaded to take same amount of current.

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

hine. b) In rotating machines, how would the voltages be generated in windings or groups of coils? c) Sketch the Full-bridge driving circuit for the permanent magnet brushless (PMBL) DC motor. Q3/
q1 a
A 240 V, DC shunt motor draws 15 A while supplying the rated load at a speed of 100 rad/s. The armature resistance is 0.5 Q and the field winding resistance is 80 Q. The net voltage across the armature resistance at the time of plugging will be
4. If the no load speed of DC motor is 1300 rpm and full load speed is 1100 rpm, then its voltage regulation is a) 12.56% b) 18.18 % c) 17.39% d) 18.39%
A DC motor should be operated in a strong field which is due to the What happens to if suddenly goes a) nothing, it continues rotating b) it over speeds c) it stops rotating current if moter if rotating to zero. as before
A 2 hp 50 Hz 3-phase 220 V delta wired induction motor has a full-load rated speed of 1400 rpm. a) How many poles does the motor have? b) Calculate its rated output torque. c) What is the slip at full load? d) If the current is 6.37 A with a power factor of 0.79 at full load, what is the efficiency of the motor? e) Calculate the torque and approximate speed at ½ load. f) If a variable frequency drive were used to control the speed of this motor, what is the approximate maximum speed for the load from e)? What frequency would the drive be set to? Please answer all subpart either dislike is ready please all subpart in short please
B3. A three-phase, 60 Hz 4-pole induction motor has a slip of 0.05 when the output is 30 kW. The frictional loss at shaft is 300 W. Calculate the following: (i) the rotor speed in r.p.m. (ii) the torque delivered by the rotor. (iii) the torque delivered to the rotor. (iv) the rotor IR loss.
A DC series motor having a resistance of 0.4 ꭥ and runs at 2000 rpm when connected to 250 V supply and drawing a current of 20 A. (i) What resistance must be added in order to limit the speed to 4000 rpm when armature current is 5A? Assume flux varies linearly. (ii) What resistance must be added to limit the speed to 1000 rpm when armature current is 30 A? Assume that the flux at 30 A is 20% more than that at 20A. (iii) At what speed the motor will run if it is connected directly to 250 V supply when the load is such that the current drawn is 30 A?