1.Which of the following property of air does not increase with rise in temperature

2.The concept of overall coefficient of heat transfer is used in case of heat transfer by

3.In free con-vection heat transfer, Nusselt number is function of

4.The unit of overall coefficient of heat transfer is

5.According to Kirchoff's law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a