Mode of heat transfer

Heat from the sun reaches to us by?

• Conduction

• Radiation

• Convection

• All of these

What is heat transfer?

• Flow of thermal energy from low-temperature reservoir to high-temperature reservoir

• Flow of energy in the form of heat from high-temperature reservoir to low-temperature reservoir

• Flow of thermal energy irrespective of reservoir temperature

• None of the above

____is the unit of rate of heat transfer

Metals ​_______on heating and _________​ on cooling.

Convection can occur in ______and _______ substances.