A thin electric heater is inserted between a long circular rod and a concentric tube with innerand outer radii of 20 and 40 mm, respectively. The steel rod (A) has a thermal conductivity ofKA = 15 W/m.K and the plastic tube (B) has a thermal conductivity of kB = 0.8 W/m.K. Theouter surface of the tube is subjected to convection with a fluid at a temperature of T = -5°Cand heat transfer coefficient of 50 W/m²K. The thermal contact resistance between the cyl-inder surfaces and the heater is negligible. (40 points)(a) Determine the electrical power per unit length (W/m) that is required to maintain theouter surface of cylinder B at 5°C for steady state conditions.(b) Based on part (a), what is the steady state temperature at the center of cylinder A?(c) If the heater is turned off, estimate the time for the steel rod to drop 15°C. Assume steelhas a density of p= 7900 kg/m³ and specific heat of c = 400 J/kg.K.Thin electric heaterToo, hTATBAtubeBrod

Step - 1:Given that,outer radii are, rA=20mm and rB=40mm.kA=15W/m.KkB=0.8W/m.KFluid temperature…

Answered: A thin electric heater is inserted…

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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