E-PolyLearning

Discussion Forum

Que. Low temperature insulation are used when the enclosure is at a temperature lower than the ambient temperature. Which one of the following is not a low temperature insulation?
a. Asbestos
b. Cork
c. Cattle hair
d. Slag wool
Correct Answer:Asbestos
Confused About the Answer? Ask fellow aspirants for Details Here
Already Know Explanation? Add it Here to help others.

More Questions Like this:

Choose the false statement
The diagram shows heat conduction through a plane wall. The surface temperature is 475 K and it radiates heat to the surroundings at 335 K. If thermal conductivity of the material is 12.5 W/m degree, find the temperature gradient. Let convective coefficient be 80 W/m² degree and radiation factor is 0.9
Most metals are good conductor of heat because of
What is the thermal conductivity of asphalt in W/m K?
The unit of thermal diffusivity is
Cork is a good insulator because
Which one is having lowest thermal conductivity?
From the concept of kinetic theory, mean travel velocity of the gas molecules is prescribed by the relation
(Where,
G = Universal gas constant
M = Molecular weight of the gas
T = Absolute temperature)
Consider the following statements:

The Fourier heat conduction equation

Q = -k A d t /d x

Presumes

i) Steady state conditions

ii) Constant value of thermal conductivity

iii) Uniform temperature at the wall surface

iv) One dimensional heat flow

Which of these statements are correct?
The heat energy propagation due to conduction heat transfer will be minimum for
Which one is having highest thermal conductivity?
The thermal conductivity and the electrical conductivity of a metal at absolute temperature are related as
The famous Fourier series is named after
The diffusion equations
Ɏ²t + q g = (1/α) (d t/d r)
Governs the temperature distribution under unsteady heat flow through a homogenous and isotropic material. The Fourier equation follows from this expression when
Thermal conductivity is defined as the heat flow per unit time
Identify the very good insulator
Consider the following parameters
(i) Composition
(ii) Density
(iii) Porosity
(iv) Structure
Then, thermal conductivity of glass wool varies from sample to sample because of variation is
Which one is not the unit of thermal conductivity?
To effect a bond between two metal plates, 2.5 cm and 15 cm thick, heat is uniformly applied through the thinner plate by a radiant heat source. The bonding must be held at 320 K for a short time. When the heat source is adjusted to have a steady value of 43.5 k W/m², a thermocouple installed on the side of the thinner plate next to source indicates a temperature of 345 K. Calculate the temperature gradient for heat conduction through thinner plate. In the diagram, the upper plate is 2.5 cm thick while the lower is 15 cm thick.
Low temperature insulation are used when the enclosure is at a temperature lower than the ambient temperature. Which one of the following is not a low temperature insulation?

Management and Accounting

Human Resource Management Marketing and Marketing Management Financial Management and Financial Markets Cost Accounting Business Statistics