A 50-cm * 50-cm circuit board that contains 121 square chips on one side is to be cooled by combined natural convection and radiation by mounting it on a vertical surface in a room at 25°C. Each chip dissipates 0.18 W of power, and the emissivity of the chip surfaces is 0.7. Assuming the heat transfer from the back side of the circuit board to be negligible, and the temperature of the surrounding surfaces to be the same as the air temperature of the room, determine the surface temperature of the chips. Evaluate air properties at a film temperature of 30°C and 1 atm pressure. Is this a good assumption?

Q: 4. A car engine with the dimensions 0.6 m high, 0.50 m-wide, and 0.8-m- long. The bottom surface of…

A: Data given-

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

A: Given, Q˙in = 1000 WT∞ = 20 °C = 293 Kh = 35 W/m2 °Cε = 0.6A = 0.02 m2

Q: Consider steady heat transfer between two large parallel plates at constant temperatures T1 = 300 K…

A: given data; ⇒temperature (T1)=300K⇒temperature(T2)=200K⇒length (L)=1cm=0.01m⇒(a) heat transfer…

Q: Consider a 1.2-m-high and 2-m-wide glass windowwith a thickness of 6 mm, thermal conductivity k =…

A: Given data Length of the plate L = 1.2 m width of the plate = 2 m thickness of the plate t= 6 mm…

Q: A 3 m2 hot black surface at 80 C is losing heat to the surrounding air at 25 C by convection with a…

A: Given                                      Area, A = 3 m2       Heat transfer coefficient, h = 12…

Q: A vertical 4-ft-high and 6-ft-wide double-pane window consists of two sheets of glass separated by a…

A: Given data: *The height and width of the double pane window is h=4 ft=48 inch and w=6 ft. *The…

Q: as a researcher in the field of heat transfer explain how you will distinguish between radiation by…

A: Black body – when incident rays fall on a body and body absorb all the energy then this type of body…

Q: How do convection and conduction work together to transfer heat?

A: Given Data⇒ Convection Conduction Problem definition⇒ Problem says How do convection and conduction…

Q: In a production facility, large brass plates of 4-cm thickness that are initially at a uniform…

A: Given data: The thickness of the plate is t=4 cm=0.04 m The initial temperature of plate is…

Q: A 2-m × 1.8-m section of wall of an industrial furnace burning natural gas is not insulated, and the…

A: Answer: The thickness of the insulation that needs to be used is 4.68 cm.

Q: A 3-m2 hot black surface at 80°C is losing heat to the surrounding air at 25°C by convection with a…

A:

Q: In a concentrated solar power plant, molten salt tank is used to store the thermal energy from the…

A:

Q: 4.2. An average person generates heat at a rate of 84W while resting in a room at T-. Assuming one-…

A: Data given-  Qtotal =84 watt = 84 J /s  The room temperature T= 26°C  emissivity of the skin ε = 0.9…

Q: Consider steady heat transfer between two large parallel plates at constant temperatures T1 = 300 K…

A:

Q: 4. A car engine with the dimensions 0.6 m high, 0.50 m-wide, and 0.8-m- long. The bottom surface of…

A:

Q: Does any of the energy of the sun reach the earth by conduction or convection?

A: Since there is no atmosphere in space between the Sun and the earth, the significant portion of the…

Q: Consider steady heat transfer between two large parallel plates at constant temperatures of T1 = 300…

A:

Q: Consider a person standing in a room maintained at20°C at all times. The inner surfaces of the…

A:

Q: Consider a person standing in a roomn at 20°C with an exposed surface area of 1.5 m2. The deep body…

A: Given Data: Deep body temperature, T1=37 C The thickness of the skin, x=0.5 cm Thermal conductivity…

Q: Consider a person standing in a room. The inner surfaces of the walls, floors, and ceiling of the…

A:

Q: = Consider a person standing in a room at 23°C. Determine the total rate of heat transfer from this…

A:

Q: A 5-m-long strip of sheet metal is being transported on a conveyor at a velocity of 5 m/s, while the…

A:

Q: An average person generates heat at a rate of 240 Btu/h while resting in a room at 70°F. Assuming…

A: The rate of heat transfer, Q = 240 Btu/h The room temperature, Ts = 70°F The emissivity of the skin,…

Q: 2-m-long, 0.3-cm-diameter electrical wire extends across a room at 15°C, Heat is generated in the…

A: Given data,L=2mD=0.3cm=0.3100m=0.003mT∞=15°C, V=60 Volt, TS=152°C,  I=1.5A°Neglecting heat transfer…

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: Consider a person standing in a room maintained at 20°C at all times. The inner surfaces of the…

A:

Q: Consider a 1.2-m-high and 2-m-wide double-pane window consisting of two 0.023-mm-thick layers of…

A:

Q: (a) A small body with temperature T and emissivity e is placed in a large evacuated cavity with…

A:

Q: Consider a sealed 20-cm-high electronic box whose base dimensions are 40 cm x 40 cm placed in a…

A: Heat transfer through radiation is equal to the power generated. The exposed area could be…

Q: Consider steady heat transfer between two large parallel plates at constant temperatures T1 = 300 K…

A:

Q: Consider a sealed 20-cm-high electronic box whose base dimensions are 40 cm × 40 cm placed in a…

A:

Q: 1.) Consider a sealed 20-cm-high electronic box whose base dimensions are 40 cm x40 cm placed in a…

A:

Q: Consider a sealed 20-cm-high electronic box whose base dimensions are 50 cm x 50 cm placed in a…

A: Data given-   Ts = 55+273 = 328 K  Heat is mainly transferred by radiation only .

Q: Consider a person whose exposed surface area is 1.5 m2, emissivity is 0.5, and surface temperature…

A: Given data: A=1.5 m2ε=0.5Tb=28°CTR1=280 KTR2=300 Kσ=5.67×10-8 W/m2.K4 Need to determine the heat…

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: Two parallel back disks are positioned coaxially with a distance of 0.25 m apart. The lower disk is…

A: Consider the diagram shown below for the given arrangement of the discs.

Q: what are the different modes of heat transfer? Explain transfer of heat by convection process?

A:

Q: Consider a person standing in a room maintained at20°C at all times. The inner surfaces of the…

A:

Q: A 2-m x 1.8-m section of wall of an industrial furnace burning natural gas is not insulated, and the…

A:

Q: Determine the net heat transferred by radiation from a 9-ft square hot plate to a cold plate of…

A:

Q: Q1: What is the difference between the forced convection and natural convection?

A: Both natural and forced convection are mode of heat tranfer in which motion of fluid takes place but…

Q: A 1000-W iron is left on the ironing board with its base exposed to the air at 23°C. The convection…

A: Given data: The power of iron, Ẇ = 1000 W. The temperature of the air, Ta = 23oC. The heat…

Q: Please check attach file

A: Given data: h = 12 m b = 2 m t = 0.023 mm k = 0.78 W/m k Separated by the vacuum = 12 mm wide h1 =…

Q: Q3. Consider a sealed 20-cm-high electronic box whose base dimensions are 40 cm x 40 cm placed in a…

A:

Q: Consider a person who is trying to keep cool on a hot summer day by turning a fan on and exposing…

A: Given: The temperature of the air, Ta = 32⁰C The velocity of air blown by the fan, u = 5 m/s The…

Q: 2.) Consider a flat plate solar collector placed horizontally on the flat roof of a house. The…

A: Formulas for convection and radiation heat transfer are used. Qconv=hAs(Ts-T∞)Qrad=εAsσ(Ts4-T∞4)