Question

What is the name of the process of heat transfer that transfers heat using electromagnetic waves?
(A) Conduction
(B) Convention
(C) Evaporation
(D) Radiation

Answer 1

Hint: Evaporation is not a method of heat transfer but is actually the phenomenon when the water is converted into vapor without reaching the boiling point. Conduction, convection and radiation are different methods of heat transfer for solid, liquid and gaseous or vacuum state.

Complete step by step solution
Heat transfer is transfer of heat through atoms of any substance or by electromagnetic waves which carries energy in the form of electric and magnetic fields. Conduction and convection are the modes of heat transfer through solid and liquid respectively. The particles at the end of the heat source absorb the heat and start vibrating. This vibration is carried further and it reaches the other end. In space, the particles are too far apart to effectively transfer heat by particle vibration. The heat transfer in space is done by using EM waves and the process is called radiation.

Therefore, the correct answer is option D.

Note: Radiation is the only method possible for transfer of heat through space or vacuum as there are no particles to transfer the heat. Light rays are a form of electromagnetic waves. These electromagnetic waves do not need a medium to travel. They propagate heat through radiation.