A 12-cm × 18-cm circuit board houses on its surface 100 closely spaced logic chips, each dissipating 0.06 W in an environment at 40°C. The heat transfer from the back surface of the board is negligible. If the heat transfer coefficient on the surface of the board is 10 W/m2·K, determine (a) the heat flux on the surface of the circuit board, in W/m2; (b) the surface temperature of the chips; and (c) the thermal resistance between the surface of the circuit board and the cooling medium, in °C/W.

A 12-cm × 18-cm circuit board houses on its surface 100 closely spaced logic chips, each dissipating 0.06 W in an environment at 40°C. The heat transfer from the back surface of the board is negligible. If the heat transfer coefficient on the surface of the board is 10 W/m2·K, determine (a) the heat flux on the surface of the circuit board, in W/m2; (b) the surface temperature of the chips; and (c) the thermal resistance between the surface of the circuit board and the cooling medium, in °C/W.

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 1.19P: 1.19 A cryogenic fluid is stored in a 0.3-m-diameter spherical container is still air. If the...

See similar textbooks

Related questions

Q: For heat transfer purposes, a standing man can be modeled as a 30-cm-diameter, 170-cm-long vertical…

Q: The wall of a furnace has a thickness of 5 cm and thermal conductivity of 0.7 W/m-°C. The inside…

Q: A 50-m-long section of a steam pipe whose outer diameter is 10 cm passes through an open space at…

Q: Consider a power transistor that dissipates 0.2 W of power in an environment at 30°C. The transistor…

A: Given data: *The power dissipated by the transistor is Q’=0.2 W. *The temperature of the environment…

Q: The inner and outer surfaces of a cyl nd

A: K = 2 W / mk r1= 1 cm , t1 = 300 degree r2 = 2 cm , T2 = 100 degree The diagram has been…

Q: A person stands in a breezy room whose temperature is 20 C. The emissivity of the person is 0.35.…

Q: The inside and outside surfaces of a 1-cm thick, 4-m squared-shaped

A: Given data⇒ Thickness (t)=1 cm=0.01 m Side of square(a)=4 m Inside temperature T1=90C=9+273T1=282 K…

Q: Heat is transferred steadily through a 0.15-m thick 3 m by 5 m wall whose thermal conductivity is…

A: Given data Thickness =0.15m Wall dimension. 3m × 5m Thermal conductivity = 1.2 W/m°C Inner…

Q: 1. A 1000-W iron is left on the iron board with its base exposed to the air at 20°C. The convection…

A: Heat Transfer

Q: A furnace wall is made of 20 cm of magnesite brick and 20 cm of common brick. The magnesite brick is…

A: Given, T1 = 1200 C T2 = 35 C L1 = 20 cm = 0.2 m L2 = 20 cm = 0.2 m hi = 40 W/m2K ho = 20 W/m2K km =…

Q: The brick wall of a house measures 4 x 7 m and has a thickness of 0.3 m. The thermal conductivity of…

A: given data as per question Dimensions of the brick wall = 4m×7m Thickness of the wall = 0.3 m…

Q: A 5 m long section of a steam pipe whose outer diameter is 10 cm passes through an open space at…

A: Given data: The length of pipe, L=5 m. The diameter of the pipe, d=10 cm. The open space…

Q: A flat surface is covered with insulation with a thermal conductivity of 0.08 W/m · K. The…

A: Thermal conductivity of insulation,K=0.08WmKTemperature at interface,TS=300οC=(300+273)K=573KHeat…

Q: The heat transfer coefficient of oil flowing through a pipe is 300 W/m2 K. Determine the heat…

Q: A thermopane window consists of two glass panes, each 0.50 cm thick, with a 1.0-cm-thick sealed…

A: Given: Thickness of each glass pane bg = 0.5 cm =0.005 m Thickness of layer of air ba = 1 cm = 0.01…

Q: Consider a 15-cm * 20-cm printed circuit board (PCB) that has electronic components on one side. The…

A: Given data: The length of the circuit board, Lc=20 cm The width of the circuit board, wc=15 cm The…

Q: A hot steel plate with a surface area of 1.93 m2 and a constant surface temperature of 169°C is…

A: The given information in the problem is shown in the following attached image:

Q: An electrical wire with a length of 5-m and 3.5-mm-Ø spreads over one room at 18°C. Heat is…

Q: A 4-mm and 2-m-long electric wire is tightly wrapped with a 2-mm-thick plastic cover whose thermal…

A: Write the given value using suitable variables. Here r1 signifies wire radius, L signifies wire…

Q: Ice water of 0°C is stored in a spherical container made of steel with an inner diameter of 3 m and…

Q: I just took a water bottle out of my refrigerator (0₁ = 3°C) and placed it on the kitchen counter.…

A: The given information in the problem is shown in the following attached image:

Q: Consider a furnace (as a plane wall) which has a thickness of 15 cm and a surface area of 1 m?. The…

A: Given: The thickness of the wall, L = 15 cm = 0.15 m The surface area of the wall, A = 1 m^2 The…

Q: Determine the heat flow (in Watts) across a plane wall of 8.1m thickness with a constant thermal…

A: given; →thickness of wall (t)=8.1m→thermal conductivity…

Q: A steel tube with a thermal conductivity of 55 W/mK carries a fluid at 175°C, with a convection heat…

Q: To warm up some milk in a thin-walled glass cylindrical container whose diameter is 6 cm. The height…

Q: A plane wall 3.5 cm thick generates heat internally. The wall is made of a material with thermal…

A: To Find : The rate of internal heat generation in the wall per unit volume.Given : The thickness of…

Q: Consider a person standing in a room at 18°C. Determine the total rate of heat transfer from this…

Q: Consider a person whose exposed surface area is 1.7 m2, emissivity is 0.9, and surface temperature…

Q: A wall with a thermal conductivity of 0.50W/m·K is maintained at 40.0°C. The heat transfer through…

A: The temperature at the outside surface is 36.67 ℃.

Q: flat wall is exposed to the environment. The wall is covered with a layer of insulation 1.0 inches…

Question

100%

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

Step 2

Step 3

Step 4

Trending now

This is a popular solution!

Step by step

Solved in 4 steps with 15 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

Similar questions

The inside and outside surfaces of a 1-cm thick, 4-m squared-shaped window glass in winter are 9°C and 1°C, respectively. If the thermal conductivity of the glass is 0.78 W/m-K, determine the heat loss, in kcal, through the glass over a period of 8 hours.
Consider a power transistor that dissipates 0.2 W of power in an environment at 30°C. The transistor is 0.4 cm long and has a diameter of 0.5 cm. Assuming heat to be transferred uniformly from all surfaces, determine (a) the amount of heat this resistor dissipates during a 24-h period, in kWh; (b) the heat flux on the surface of the transistor, in W/m2; and (c) the surface temperature of the resistor for a combined convection and radiation heat transfer coefficient of 18 W/m2·K.
A plane wall 3.5 cm thick generates heat internally. The wall is made of a material with thermal conductivity of 44 W/m K. Both faces of the wall are maintained at 50.30°C. If the maximum temperature inside the wall is 61°C, what is the rate of internal heat generation in the wall per unit volume? Express your answer in W/m³.
A furnace wall is made of 20 cm of magnesite brick and 20 cm of common brick. The magnesite brick is exposed to hot gases at 1200°C and common brick outer surface is exposed to 35°C room air. The surface heat transfer coefficient of the inside wall is 40 W/m²K and that of the outer wall is 20 W/m²K respectively. Thermal conductivities of magnesite and common brick are 4 and 0.5 W/mK respectively. Determine: i. Heat loss per m² of area of the furnace wall and ii. Maximum temperature to which common brick is subjected
A 5 m long section of a steam pipe whose outer diameter is 10 cm passes through an open space at 30°C. The average temperature of the outer surface of the pipe is measured to be 150°C, and the average heat transfer coefficient on that surface is determined to be 180 W/m^2.k. Determine (a) the rate of heat loss through convection from the steam pipe and (b) the annual cost of this energy loss if steam is generated in a natural gas furnace, and the price of natural gas is 0.05 Rs/Kwh, consider a 250 working-day year.
An electrical wire with a length of 5-m and 3.5-mm-Ø spreads over one room at 18°C. Heat is generated in the wire due to resistance heating with a convection heat transfer coefficient of 23 W/m2-K between the outer surface of the wire and the air in the room. The voltage drop and electric current through the wire are measured to be 60 V and 2 A, respectively. Disregarding any heat transfer by radiation, determine the surface temperature of the wire (°C). Surface Temp. of Wire (°C) =
Heat is transferred steadily through a 0.15-m thick 3 m by 5 m wall whose thermal conductivity is 1.2 W/m.°C. The inner and outer surface temperatures of the wall are measured to be 18°C to 4°C. Determine the rate of heat conduction through the wall?
A thermopane window consists of two glass panes, each 0.50 cm thick, with a 1.0-cm-thick sealed layer of air in between. (a) If the inside surface temperature is 22.1°C and the outside surface temperature is 0.0°C, determine the rate of energy transfer through 1.40 m² of the window. W (b) Compare your answer to (a) with the rate of energy transfer through 1.40 m² of a single 1.0-cm-thick pane of glass. Disregard surface air layers. (Find the rate of energy transfer.) kW
The wall of a furnace has a thickness of 5 cm and thermal conductivity of 0.7 W/m-°C. The inside surface is heated by convection with a hot gas at 402°C and a heat transfer coefficient of 37 W/m-°C. The outside surface has an emissivity of 0.8 and is exposed to air at 27°C with a heat transfer coefficient of 20 W/m-°C. Assume that the furnace is inside a large room with walls, floor and ceiling at 27°C. Show the thermal circuit and determine the heat flux through the furnace wall.
Consider a 15-cm * 20-cm printed circuit board (PCB) that has electronic components on one side. The board is placed in a room at 20°C. The heat loss from the back surface of the board is negligible. If the circuit board is dissipating 8 W of power in steady operation, determine the average temperature of the hot surface of the board, assuming the board is (a) vertical, (b) horizontal with hot surface facing up, and (c) horizontal with hot surface facing down. 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. Evaluate air properties at a film temperature of 32.5°C and 1 atm pressure. Is this a good assumption?
Consider a person standing in a room at 18°C. Determine the total rate of heat transfer from this person if the exposed surface area and the skin temperature of the person are 1.7 m2 and 32°C. respectively, and the convection heat transfer coefficient is 5 W/m2-K. Take the emissivity of the skin and the clothes to be 0.9, and assume the temperature of the inner surfaces of the room to be the same as the air temperature.
I just took a water bottle out of my refrigerator (0₁ = 3°C) and placed it on the kitchen counter. The environment is at 0₂ = 20 °C. The overall heat transfer coefficient between the bottle and the environment is 2 W/K and the heat capacity of the bottle and its contents is 3 kJ/K. Over what time periods would you consider the bottle to be an adiabatic system? A diather- Colar mal system?