Question

which of the following is the best definition of radiation? a. the transmission of heat without any contact b. the transfer of heat by currents within a liquid or gas c. the transfer of heat by electrical currents d. the transmission of heat across matter

Explanation:

Radiation is the transmission of heat energy through space without the need for a medium (i.e., without any contact between the heat - source and the object receiving the heat). Option B describes convection, option C is not a common heat - transfer mechanism related to the general definition of radiation, and option D is more related to conduction.

Answer:

A. the transmission of heat without any contact