In which of the following ways of heat transfer no medium is required?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. Radiation.
Heat can be transferred in three ways: conduction, convection, and radiation. Among these, radiation does not require any medium for transfer. It occurs through electromagnetic waves, allowing heat to travel even through the vacuum of space. For example, the Sun’s heat reaches the Earth through radiation, despite the vast emptiness between them. In contrast, conduction needs direct contact between particles, and convection requires a fluid medium like air or water. Therefore, radiation is the only method where heat energy can move without relying on matter, making it essential for energy transfer in space and other vacuum environments.