Q3: Consider a (15cm x 20cm) printed circuit board (PCB) that has electronic components on one side as shown in the figure. The board is placed in a room at 20°C. The heat loss from the back surface of the board is negligible. The surface temperature of circuit board is 46°C. Determine the total heat loss by convection and radiation if the board is vertical, Take the emissivity of the surface of the board to be 0.8 and assume the surrounding surfaces to be at the same temperature as the air in the room. (Answers: 8W) Hint: The properties of the air at latm. are as follow: k = 0.02607 W/m. C v =1.631x10 m³/s Pr = 0.7275 Insulation PCB, T, L= 0.2 mh Air T = 20°C

Q3: Consider a (15cm x 20cm) printed circuit board (PCB) that has electronic components on one side as shown in the figure. The board is placed in a room at 20°C. The heat loss from the back surface of the board is negligible. The surface temperature of circuit board is 46°C. Determine the total heat loss by convection and radiation if the board is vertical, Take the emissivity of the surface of the board to be 0.8 and assume the surrounding surfaces to be at the same temperature as the air in the room. (Answers: 8W) Hint: The properties of the air at latm. are as follow: k = 0.02607 W/m. C v =1.631x10 m³/s Pr = 0.7275 Insulation PCB, T, L= 0.2 mh Air T = 20°C

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.56P: A pipe carrying superheated steam in a basement at 10C has a surface temperature of 150C. Heat loss...

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Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.

Question

Q3: Consider a (15cm x 20cm) printed circuit board (PCB) that has electronic components on
one side as shown in the figure. The board is placed in a room at 20°C. The heat loss from the
back surface of the board is negligible. The surface temperature of circuit board is 46°C.
Determine the total heat loss by convection and radiation if the board is vertical, Take the
emissivity of the surface of the board to be 0.8 and assume the
surrounding surfaces to be at the same temperature as the air in the room.
(Answers: 8W)
Hint: The properties of the air at latm. are as follow:
k = 0.02607 W/m. C
v =1.631x10 m³/s
Pr = 0.7275
Insulation
PCB, T,
8W
L= 0.2 mh
Air
T = 20°C

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