omework chapter one:-W. 1.1 it is required to maintain a loading of 5 kW in a heating unit. At an initialtemperature of 15 C°, a voltage of 200 V is necessary for this purpose. When the unit issettled down to a steady temperature, a voltage of 220 V is required to maintain the sameloading. Estimate the final temperature of the heating element, if the resistancetemperature coefficient of the heating element is 0.0006 per C° at 0 Co.Answer: t2 = 368.15 C°H.W. 1.2: Determine the current flowing at the instant of switching a 60 watt lamp on a230 V supply. The ambient temperature is 25 Co. The filament temperature is 2000 Cand the resistance temperature coefficient is 0.005 /C° at 0 C°.Answer: I = 2.548 AH.W.1.3: At 0 C°, a specimen of copper wire has its resistance equal to 4-milliohm andits temperature coefficient of resistance equal to (1/234.5) per Co. Find the values of itsresistance and temperature coefficient of resistance at 70 Co.Answer: Rt = 5.194 m2, a70= 0.003284/ C°H.W. 1.4: At 0 C°, the resistances and their temperature coefficients of resistance of tworesistors 'A and 'B' are 80 ohm and 120 ohm, and 0.0038 per Co and 0.0018 per Co,respectively. Find the temperature-coefficient of resistance at 0 Co of their seriescombination.Answer: a12 = 2.6 x 103 /C°H.W. 1.5: A D.C. shunt motor, after running several hours on constant voltage of 400 V,takes field current of 1.6 A. 1f temperature rise is 40 C°, what value of extra resistance isrequired in field circuit to maintain field current equal to 1.6 A. Assume motor startedfrom cold at 20 C° and a20 = 00043/C°.Answer: Rx = 36.6894 2

Answered: Image /qna-images/answer/eba582d6-1a8e-4aac-a75a-8f94abb405a3.jpg

H.W. 1.5: A D.C. shunt motor, after running several hours on constant voltage of 400 V, takes field current of 1.6 A. 1f temperature rise is 40 C°, what value of extra resistance is required in field circuit to maintain field current equal to 1.6 A. Assume motor started from cold at 20 C° and a20 = 00043/C°. Answer: Rx = 36.6894 2

H.W. 1.5: A D.C. shunt motor, after running several hours on constant voltage of 400 V, takes field current of 1.6 A. 1f temperature rise is 40 C°, what value of extra resistance is required in field circuit to maintain field current equal to 1.6 A. Assume motor started from cold at 20 C° and a20 = 00043/C°. Answer: Rx = 36.6894 2

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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