Which of the following is the fastest process of heat transfer?

Which of the following is the fastest process of heat transfer? Radiation is the fastest mode of heat transfer while conduction is the slowest mode of heat transfer. Radiation is defined as the mode of heat transfer which takes place through the vacuum and doesn’t require any physical medium.

What is the fastest process of heat transfer? Radiation: Thermal radiation generated from electromagnetic waves. Radiation occurs through vacuum or any other material medium. The heat is transferred at the speed of the electromagnetic wave in the medium, which is the speed of light in the medium. So radiation is the fastest among the three due to this reason.