Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion
Discussion Forum : Heat Transfer, Refrigeration and Air Conditioning - Section 1 (Q.No. 3)
3.
Which of the following statement is wrong?
Discussion:
31 comments Page 2 of 4.
Netrapal said:
9 years ago
Thermal conductivity is directly proportional to temperature gradient.
Pradeep said:
9 years ago
Not only convection. Heat flow in still water also occurs due to conduction. Hence option A is partially correct.
Atif said:
9 years ago
For metals, the thermal conductivity is mainly a function of the motion of free electrons. As the temperature increases, the molecular vibrations increase (in turn decreasing the mean free path of molecules). So, they obstruct the flow of free electrons, thus reducing the conductivity.
Gnagadharac rao said:
9 years ago
Thermal conductivity depends on the metal property, and not temperature.
Amrit said:
9 years ago
Actually, thermal conductivity varies differently in the different physical state of matter. In solid if temperature increases then thermal conductivity decreases (for). In gas if temperature increases thermal conductivity increases. And for liquid, it depends on upon the temperature.
Rahul raja said:
9 years ago
As the resistance is more in the path of a solid body there will be more collision due to which thermal conductivity of solid decreases.
Friend said:
10 years ago
Just remember that perfect conduction can be achieved at sub zero temperature state called superconducting that means as the temperature decreases conductivity increases. Hence it would be easy to remember that as temperature increases conductivity decreases.
Friend said:
10 years ago
Just remember that perfect conduction can be achieved at sub zero temperature state called superconducting that means as the temperature decreases conductivity increases. Hence it would be easy to remember that as temperature increases conductivity decreases.
Rohan said:
10 years ago
If temperature of solid is increased it will expand thus its molecules will get separated thus reducing the thermal conductivity?
Ravi kumar said:
1 decade ago
For pure metals temperature increases k value decreases for alloys it will increases.
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