Thermal conductivity of insulating materials

Assignment Help Electrical Engineering
Reference no: EM13879636

A hollow aluminum sphere, with an electrical heater in the center, is used in tests to determine the thermal conductivity of insulating materials. The inner and outer radii of the sphere are 0.15 and 0.18 m, respectively, and testing is done under steady-state conditions with the inner surface of the aluminum maintained at 250°C. In a particular test, a spherical shell of insulation is cast on the outer surface of the sphere to a thickness of 0.12 m. The system is in a room for which the air temperature is 20°C and the convection coefficient at the outer surface of the insulation is 30 W/m2 · K. If 80 W are dissipated by the heater under steady-state conditions, what is the thermal conductivity of the insulation?

Reference no: EM13879636

Questions Cloud

Process of interpreting the client dreams : If a counselor is aware of the cultural background of a client, the process of interpreting the client's dreams will be fairly straightforward
Set up an lp model in general form : Set up this decision problem as an LP model in general form.
French company, prepares its financial statements : 1.Air France KLM (AF) , a French company, prepares its financial statements according to International Financial Reporting Standards.
What is the current state of the us economy? define how gdp : What is the current state of the US economy? Define how GDP is doing in each of its components (Consumption, Investment, Government Purchases and Net Exports).
Thermal conductivity of insulating materials : A hollow aluminum sphere, with an electrical heater in the center, is used in tests to determine the thermal conductivity of insulating materials.
Prepare a journal article about indigenous psychologies : Imagine you are asked to prepare a journal article about "indigenous psychologies."
Give illustrative examples for attainability set reflexion : Give definitions and illustrative examples for the following terms: Attainability set Reflexion and First-kind reflexion. Second-kind reflexion Informational reflexion Strategic reflexion.
Set up the general form of the lp model : Set up the general form of the LP model for the following word problem. A cash grain farmer in Central Iowa has 600 acres of cropland available on which she plans to grow corn and soybeans in the spring of 2011. She has made some budgets, which ta..
Identify two microeconomics and two macroeconomics principle : Identify two microeconomics and two macroeconomics principles or concepts

Reviews

Write a Review

Electrical Engineering Questions & Answers

  What is the fundamental benefit of plc controls

1.Calculate motor speed in revolutions per minute for an eight-pole,50Hz motor. Give the equation and identify its parts; show your math. 2.You need to detect finished products coming down an assembly line.

  Find what is the frequency f and period t of the wave in air

An ND:YAG laser in the lab emits light at 1064 nm. The laser is light is directed into a slab of silicon, which has an index of refraction n = 4. a. What is the relative permittivity of Si at this wavelength (Hint: Si is non-magnetic.)

  Digital communications -order the following modulation types

Digital Communications, Order the following modulation types in terms of spectral efficiency (best to worse) and explain

  Design a system that repeatedly computes and outputs

Design a system that repeatedly computes and outputs the sum of all positive numbers within a 512 word register file A consisting of 32-bit signed numbers.

  1 you will create a data set consists of the total data

1 you will create a data set consists of the total data number elements. for example if your total data number is 127

  Determine how many bits must the adc have

An LVDT with associated signal conditioning will be used to measure work-piece motion from -20 to +20 cm. The static transfer function is 2.5 mV/mm. The output will be interfaced to a computer via an ADC.

  Find overall efficiency of hydroelectric generating station

in a hydroelectric generating station the difference in level between ,the water surface and turbine driving the generators is 425 meters.if 1250 liters of water is required to generate 1 kwh of electric energy.find the overall efficiency

  What senses 3 accelerometer readings into pins

Write C code that senses 3 accelerometer readings into pins PAD 8, 9 and 10 and displays them on the LCD. Also run a timer in seconds and log the values of the accelerometers in 3 arrays every second.

  Plot the step and impulse response of the system

Assume the output is taken from the capacitor in this RC system with R=200Ohm and C=1µF. Plot the step and impulse response of the system by using the LSIM (you can use TF function before LSIM to calculate your system coefficients) function of MATLAB..

  Design the circuit with a decoder and external gates

A combinational circuit is defined by the following three Boolean functions. Design the circuit with a decoder and external gates. f = x y z + xz g = x y z + xy h = x yz + xy

  Convert the twos compliment numbers to decimal

Convert the following Two's Compliment numbers to decimal: 1) 0101 1110 10112C 2) 1001 1111 10002C 3) 1111 1111 11112C 4) -1001 0110 10012C  5) 1010 1010 10102C 6) 1000 0000 00002C

  Design a simple power factor meter to operate from mains

1. design a simple power factor meter to operate from 230v mains. current range=1 to 10 amps. power factor range : 0.4 to 1 2. what is meant by normal mode rejection an A/D converter has 20ms integration time.

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd