In which of the following phenomena do heat waves travel along a straight line with the speed of light ?
Thermal conduction
Thermal convection
Thermal radiation
Both, thermal conduction and radiation
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-2 – 2019
The correct option is C) Thermal radiation. Heat transfer by radiation involves electromagnetic waves, which travel at the speed of light.
Heat can be transferred by conduction, convection, and radiation. Conduction is the transfer of heat through direct contact via vibrations of particles. Convection is the transfer of heat through the movement of fluids (liquids or gases). Both conduction and convection require a medium and the speed of heat transfer is much slower than the speed of light. Radiation is the transfer of heat through electromagnetic waves, such as infrared radiation. These waves can travel through a vacuum and propagate at the speed of light (approximately 3 x 10⁸ m/s in vacuum).