Test: Basic Concepts of Heat Transfer - 1

Consider the following statements pertaining to heat transfer processes:
1. Heat transfer is directly linked with the transport of medium itself, i.e., there is actual motion of heated particles during convection.
2. The material medium between the heat source and receiver is not affected during the process of heat transmission by radiation.
3. Heat transfer in liquids and gases is essentially due to radiation.
4. In gases and liquids, conduction is due to the collisions and diffusion of the molecules during their random motion.
Select the correct answer:

All the three modes of heat transfer are involved in

The essential condition for the transfer of heat from one body to another is.

Consider the following statements:
1. The thermal conductivity of a material is it’s ability to conduct heat.
2. The thermal conductivity can be defined as the rate of heat transfer through a unit thickness of the material per unit area.
3. In solids, heat conduction is due to lattice vibrational energy as well as energy transported via free flow of electrons.
4. Convection involves combined effect of conduction and fluid motion.
Which of the above statements are valid?

Thermal conductivity of wood depends on

Temperature of steam at around 540°C can be measured by

Cork is a good insulator because it has