Passage of an electric current through a long conducting rod of radius r; and thermal conductivity kr, esults in uniform volumetric heating at a rate of q.. The conduction rod is wrapped in an electrically non-conducting cladding material of radius ro and thermal conductivity ke and convection cooling is provided by an adjoining fluid. For steady-state conditions, a) Determine an expression for the heat transfer per unit length q', passing through the cladding in terms of 9, and ri. b) Determine an expression for T, the temperature of the cladding at 7; and also for To at ro. c) Calculate these cladding temperatures in °C when r and ro are 3 mm and 5 mm, ġ. = 200 kW/m³, ke = 0.15 W/m/K, T = 20°C and h = 20 W/m²/K. Conducting rod, å, k, Cladding, k d) Calculate the critical radius. To decrease the internal cladding temperature would it be necessary to increase or decrease ro; or should it remain unchanged? Explain. Th 201

Passage of an electric current through a long conducting rod of radius r; and thermal conductivity kr, esults in uniform volumetric heating at a rate of q.. The conduction rod is wrapped in an electrically non-conducting cladding material of radius ro and thermal conductivity ke and convection cooling is provided by an adjoining fluid. For steady-state conditions, a) Determine an expression for the heat transfer per unit length q', passing through the cladding in terms of 9, and ri. b) Determine an expression for T, the temperature of the cladding at 7; and also for To at ro. c) Calculate these cladding temperatures in °C when r and ro are 3 mm and 5 mm, ġ. = 200 kW/m³, ke = 0.15 W/m/K, T = 20°C and h = 20 W/m²/K. Conducting rod, å, k, Cladding, k d) Calculate the critical radius. To decrease the internal cladding temperature would it be necessary to increase or decrease ro; or should it remain unchanged? Explain. Th 201

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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