Explanation Given: The power of the transistor is 25W. Maximum temperature of the transistor is 55 ° C . Ambient air temperature is 18 ° C . Calculation: Calculate the thermal resistance from the rate of heat transfer. Q ˙ = T − T ∞ R c a s e − a m b i e n t R c a s e − a m b i e n t = T − T ∞ Q ˙ R c a

5th Edition

ISBN: 9780078027680

Author: Yunus A. Cengel Dr., Robert H. Turner, John M. Cimbala

Publisher: McGraw-Hill Education

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Chapter 17, Problem 118P

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An appropriate heat sink for the transistor.

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Chapter 17, Problem 117P

Chapter 17, Problem 119RQ

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Chapter 17 Solutions

Fundamentals of Thermal-Fluid Sciences

Ch. 17 - Prob. 1P Ch. 17 - Consider heat conduction through a plane wall....Ch. 17 - What does the thermal resistance of a medium...Ch. 17 - Can we define the convection resistance for a unit...Ch. 17 - Consider steady heat transfer through the wall of...Ch. 17 - How is the combined heat transfer coefficient...Ch. 17 - Why are the convection and the radiation...Ch. 17 - Consider steady one-dimensional heat transfer...Ch. 17 - Someone comments that a microwave oven can be...Ch. 17 - Consider two cold canned drinks, one wrapped in a...

Ch. 17 - Consider a surface of area A at which the...Ch. 17 - How does the thermal resistance network associated...Ch. 17 - Consider steady one-dimensional heat transfer...Ch. 17 - Consider a window glass consisting of two...Ch. 17 - Prob. 15P Ch. 17 - Prob. 16P Ch. 17 - Prob. 17P Ch. 17 - Prob. 18P Ch. 17 - Prob. 19P Ch. 17 - Consider a power transistor that dissipates 0.2 W...Ch. 17 - A 1.0 m × 1.5 m double-pane window consists of two...Ch. 17 - Consider a 1.2-m-high and 2-m-wide glass window...Ch. 17 - Prob. 23P Ch. 17 - Prob. 24P Ch. 17 - Prob. 26P Ch. 17 - Prob. 27P Ch. 17 - Prob. 28P Ch. 17 - Prob. 29P Ch. 17 - Prob. 30P Ch. 17 - A 2-m × 1.5-m section of wall of an industrial...Ch. 17 - The wall of a refrigerator is constructed of...Ch. 17 - Prob. 34P Ch. 17 - Prob. 35P Ch. 17 - Prob. 36P Ch. 17 - What is thermal contact resistance? How is it...Ch. 17 - Will the thermal contact resistance be greater for...Ch. 17 - Explain how the thermal contact resistance can be...Ch. 17 - A wall consists of two layers of insulation...Ch. 17 - A plate consists of two thin metal layers pressed...Ch. 17 - Consider two surfaces pressed against each other....Ch. 17 - Prob. 43P Ch. 17 - Prob. 44P Ch. 17 - Prob. 45P Ch. 17 - Prob. 46P Ch. 17 - Prob. 47P Ch. 17 - Prob. 48P Ch. 17 - Prob. 49P Ch. 17 - Prob. 50P Ch. 17 - Prob. 51P Ch. 17 - Prob. 52P Ch. 17 - Prob. 53P Ch. 17 - When plotting the thermal resistance network...Ch. 17 - Prob. 55P Ch. 17 - Prob. 56P Ch. 17 - Prob. 57P Ch. 17 - A typical section of a building wall is shown in...Ch. 17 - Prob. 59P Ch. 17 - Prob. 61P Ch. 17 - Prob. 62P Ch. 17 - Prob. 63P Ch. 17 - In an experiment to measure convection heat...Ch. 17 - What is an infinitely long cylinder? When is it...Ch. 17 - Can the thermal resistance concept be used for a...Ch. 17 - Consider a short cylinder whose top and bottom...Ch. 17 - Prob. 68P Ch. 17 - 50-m-long section of a steam pipe whose outer...Ch. 17 - Superheated steam at an average temperature 200°C...Ch. 17 - Steam exiting the turbine of a steam power plant...Ch. 17 - Repeat Prob. 17–72E, assuming that a 0.01-in-thick...Ch. 17 - A 2.2-mm-diameter and 10-m-long electric wire is...Ch. 17 - Prob. 76P Ch. 17 - Chilled water enters a thin-shelled 5-cm-diameter,...Ch. 17 - Steam at 450°F is flowing through a steel pipe (k...Ch. 17 - Prob. 79P Ch. 17 - Prob. 80P Ch. 17 - An 8-m-internal-diameter spherical tank made of...Ch. 17 - What is the critical radius of insulation? How is...Ch. 17 - Consider an insulated pipe exposed to the...Ch. 17 - A pipe is insulated to reduce the heat loss from...Ch. 17 - Prob. 86P Ch. 17 - Prob. 87P Ch. 17 - A 0.083-in-diameter electrical wire at 90°F is...Ch. 17 - Prob. 89P Ch. 17 - Prob. 90P Ch. 17 - Prob. 92P Ch. 17 - What is the reason for the widespread use of fins...Ch. 17 - What is the difference between the fin...Ch. 17 - The fins attached to a surface are determined to...Ch. 17 - Explain how the fins enhance heat transfer from a...Ch. 17 - How does the overall effectiveness of a finned...Ch. 17 - Hot water is to be cooled as it flows through the...Ch. 17 - Consider two finned surfaces that are identical...Ch. 17 - The heat transfer surface area of a fin is equal...Ch. 17 - Prob. 101P Ch. 17 - Prob. 102P Ch. 17 - Two plate fins of constant rectangular cross...Ch. 17 - Two finned surfaces are identical, except that the...Ch. 17 - A 4-mm-diameter and 10-cm-long aluminum fin (k =...Ch. 17 - Consider a very long rectangular fin attached to a...Ch. 17 - Consider a stainless steel spoon (k = 8.7...Ch. 17 - A DC motor delivers mechanical power to a rotating...Ch. 17 - A plane wall with surface temperature of 350°C is...Ch. 17 - Prob. 111P Ch. 17 - Steam in a heating system flows through tubes...Ch. 17 - Prob. 113P Ch. 17 - A hot surface at 100°C is to be cooled by...Ch. 17 - Prob. 116P Ch. 17 - A 40-W power transistor is to be cooled by...Ch. 17 - Prob. 118P Ch. 17 - Prob. 119RQ Ch. 17 - Cold conditioned air at 12°C is flowing inside a...Ch. 17 - Prob. 121RQ Ch. 17 - Prob. 122RQ Ch. 17 - Prob. 123RQ Ch. 17 - Prob. 124RQ Ch. 17 - Prob. 125RQ Ch. 17 - Prob. 126RQ Ch. 17 - Prob. 127RQ Ch. 17 - Prob. 128RQ Ch. 17 - Prob. 129RQ Ch. 17 - Prob. 130RQ Ch. 17 - Prob. 131RQ

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