6- One way of measuring the thermal conductivity of a material is to sandwich an electric thermofoil heater between two identical rectangular samples of the material and to heavily insulate the four outer edges, as shown in the figure. Thermocouples attached to the inner and outer surfaces of the samples record the temperatures. During an experiment, two 0.5-cm-thick samples 10 cm x 10 cm in size are used. When steady operation is reached, the heater is observed to draw 35Wof electric power, and the temperature of each sample is observed to drop from 82°C at the inner surface to 74°C at the outer surface. Determine the thermal conductivity of the material at the average temperature.

6- One way of measuring the thermal conductivity of a material is to sandwich an electric thermofoil heater between two identical rectangular samples of the material and to heavily insulate the four outer edges, as shown in the figure. Thermocouples attached to the inner and outer surfaces of the samples record the temperatures. During an experiment, two 0.5-cm-thick samples 10 cm x 10 cm in size are used. When steady operation is reached, the heater is observed to draw 35Wof electric power, and the temperature of each sample is observed to drop from 82°C at the inner surface to 74°C at the outer surface. Determine the thermal conductivity of the material at the average temperature.

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 1.4P: 1.4 To measure thermal conductivity, two similar 1-cm-thick specimens are placed in the apparatus...

See similar textbooks

Related questions

Q: 1. Question 1- Laplace Equation: Leibmann's Method The four sides of a square plate of side 12cm,…

Q: Please provide accurate answer with proper steps The wall of the furnace is 30.48 mm thick and…

A: Givenk=0.1W/mKt=30.48mm=0.03048mk2=0.01 W/mKT1=650oCTa=30oT2=100oC

Q: An insulation layer of 20 mm thick refractory material is placed on top of a layer of mineral wool…

Q: The composite wall of an oven consists of three materials, two of which are of known thermal…

Q: The inner and outer radii of a hollow cylinder are 15 mm (r,) and 25 mm (r, ), respectively. The…

Q: A mechanic needs to remove a tight fitting pin of material A from a hole in a block made of material…

A: GIVEN TOPIC- Thermal expansion of metals A mechanic needs to remove a tight…

Q: Question 5: A copper bar 35 cm long, with square cross-section 2 cm x 2 cm is fitted with a…

Q: A pipe wall with inner and outer radii ri and r0, whose temperatures are kept in Tİ and T0, is…

A: Given: Inner radii=ri outer radii=ro inner temperature=Ti Outer temperature=To k=k0(1+aT) Length is…

Q: . A 10-in nominal pipe (outside diameter = 10.75in) is covered with a composite pipe insulation…

Q: A square piece is initially at 10 degrees Celsius everywhere. Each side is 0.05 m long. Then the…

A: To solve this problem, we can use the heat equation to model the temperature distribution in the…

Q: 2. A brass ring of diameter 10.00 cm at 20.0°C is heated and slipped over an aluminum rod of…

A: Solution:

Q: Q1. Consider the composite cylinder of inner diameter of 80 mm, shown in figure. Assume one…

A: Heat transfer Heat transfer is a process in which heat is transfer from high temperature to low…

Q: 2. A copper segment of length 1.8 m with the cross-sectional area of 0.03 m² is welded to an…

A: Given data:

Q: A wall of a house is made from two layers of bricks enclosing a layer of insulation. A radiator is…

Q: Q1. Consider the composite materials shown in figure. 1. Sketch the equivalent thermal resistance.…

A: To find: Heat transfer per unit area of the wall, the temperatures at the interface between the…

Q: thermal conductivity of beef?

A: Given: Q=0.8 W Thickness =1 cm Cross section=5x5 Surface temperatures, T1=28.5 CT2=23.3 C TO…

Q: 1. For a steam pipe with a given diameter of 10 cm covered by two (2) layers of insulation. The…

A: (a) Write the data given in the problem. T2=27°C r1=10 cm2 =5 cm r2=5 cm+4 cm =9 cm r3=9…

Q: 1b.Consider a 1.2-m-high and 2-m-wide double-pane window consisting of two 3-mm-thick layers of…

Q: A hollow square box is made from 1ft^2 sheets of a prototype insulating material that is 0.75 inches…

Q: 1a.A copper slab (k = 372 W/m .K ) is 3mm thick . it is protected from the corrosion on each side by…

A: we are to determine the temperature distribution in the copper slab

Q: • 1. A wall 2 cm thick is to be constructed from material that has an average thermal conductivity…

A: GIVEN DATA- WALL THICKNESS=2cm TEMPRATURE DIFFERENCE= 1300-30 = 1270'C WALL THERMAL CONDUCTIVITY…

Q: The figure shows a thermal system involving two compartments with one containing a heater. The…

A: We have given

Q: QI- Consider the composite structure shown in the figure. 1. sketch the equivalent thermal…

Q: piece made of pure aluminum has a diameter D = a.x ^ 1/2 and a = 0.5m ^ 1/2. The left edge surface…

Q: A boiler furnace wall must have a heat loss no greater than 700 Btu/hr~ft2 and is made of a material…

A: Givenq=700 Btu/hr ft2k=0.60 Btu/hr-ft -FT1==2000oFT2=800oF

Q: hermal conductivity of the layers and temperatures are shown conduction, answer the following…

A: ka=2W/m°Ckb=1W/m°Ckc=5W/m°Ckd=4W/m°CLet T1, T2, T3, T4 be the temperatures at the start of section…

Q: 2. One end of a 40 cm metal rod 2.0 cm2 in cross section is in a steam bath while the other end is…

A: Length of the bar, L=40 cm=0.4 m Area of cross-section, A=2 cm2=0.002 m2 Steam Temperature Ts=100 C…

Q: A heating element made of tungsten wire is connected to a large battery that has negligible internal…

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

6- One way of measuring the thermal conductivity of a material is to sandwich an electric thermofoil
heater between two identical rectangular samples of the material and to heavily insulate the four outer
edges, as shown in the figure. Thermocouples attached to the inner and outer surfaces of the samples
record the temperatures.
During an experiment, two 0.5-cm-thick samples 10 cm x 10 cm in size are used. When steady
operation is reached, the heater is observed to draw 35Wof electric power, and the temperature of each
sample is observed to drop from 82°C at the inner surface to 74°C at the outer surface. Determine the
thermal conductivity of the material at the average temperature.
A

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 Introduction

VIEW

Step 2 Solution

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 2 steps

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

1.63 Liquid oxygen (LOX) for the space shuttle is stored at 90 K prior to launch in a spherical container 4 m in diameter. To reduce the loss of oxygen, the sphere is insulated with superinsulation developed at the U.S. National Institute of Standards and Technology's Cryogenic Division; the superinsulation has an effective thermal conductivity of 0.00012 W/m K. If the outside temperature is on the average and the LOX has a heat of vaporization of 213 J/g, calculate the thickness of insulation required to keep the LOX evaporation rate below 200 g/h.
1.4 To measure thermal conductivity, two similar 1-cm-thick specimens are placed in the apparatus shown in the accompanying sketch. Electric current is supplied to the guard heater, and a wattmeter shows that the power dissipation is 10 W. Thermocouples attached to the warmer and to the cooler surfaces show temperatures of 322 and 300 K, respectively. Calculate the thermal conductivity of the material at the mean temperature in W/m K. Problem 1.4
1.3 A furnace wall is to be constructed of brick having standard dimensions of Two kinds of material are available. One has a maximum usable temperature of 1040°C and a thermal conductivity of 1.7 W/(m K), and the other has a maximum temperature limit of 870°C and a thermal conductivity of 0.85 W/(m K). The bricks have the same cost and are laid in any manner, but we wish to design the most economical wall for a furnace with a temperature of 1040°C on the hot side and 200°C on the cold side. If the maximum amount of heat transfer permissible is 950 , determine the most economical arrangement using the available bricks.
2.51 Determine by means of a flux plot the temperatures and heat flow per unit depth in the ribbed insulation shown in the accompanying sketch.
2.30 An electrical heater capable of generating 10,000 W is to be designed. The heating element is to be a stainless steel wire having an electrical resistivity of ohm-centimeter. The operating temperature of the stainless steel is to be no more than 1260°C. The heat transfer coefficient at the outer surface is expected to be no less than in a medium whose maximum temperature is 93°C. A transformer capable of delivering current at 9 and 12 V is available. Determine a suitable size for the wire, the current required, and discuss what effect a reduction in the heat transfer coefficient would have. (Hint: Demonstrate first that the temperature drop between the center and the surface of the wire is independent of the wire diameter, and determine its value.)
I need a step by step answer please :)
A pipe wall with inner and outer radii ri and r0, whose temperatures are kept in Tİ and T0, is discussed. The heat conduction coefficient of the cylinder depends on the temperature, and k =k0(1 + aT)relationship can be written as ko and one constant. Subtract an equation for the heat passing through the unit length of the pipe. What is the thermal resistance of the pipe wall.
One more time. PLEASE explain how the integral is formed, dT/dr doesn't make sense. Why we are replacing L with dr? dr is in radial direction and L is in the vertical direction.
Please provide accurate answer with proper steps The wall of the furnace is 30.48 mm thick and is insulated from outside. Thermal conductivity of the wall material is 0.1 W/m K and the insulation material is 0.01 W/m K. The furnace operates at 650 0C and the ambient temperature is 30 0 Allowable temperature on the outer side of the insulation is 1000C. Determine the overall heat transfer by conduction per unit area occurring across a furnace wall made from clay. If the air side heat transfer coefficient is 0.4 W/m2 K, calculate the minimum insulation thickness requirement.
Answer correctly and quickly as possible please.
Question is iamge
A hollow square box is made from 1ft^2 sheets of a prototype insulating material that is 0.75 inches thick. A 120W electrical heater is placed inside the box. Over time thermocouples attached to the box show that the interior and exterior surfaces of one face have reached the constant temperatures of 150 degrees and 90 degrees. What is the thermal conductivity?