Question

A) Heat transfer by conduction and convection require a material medium.

B) Heat transfer by radiation doesn't require a material medium.

• A. both A and B are true
• B. A is true but B is false
• C. B is true but A is false
• D. both A and B are false

Answer 1

Answer: (A)

both A and B are true

Conduction and convection are processes where heat is transferred by the collision of molecules. Hence, for these processes to take place, we need a material medium.
In radiation, heat travels as electromagnetic waves which do not require a medium to travel. Its transfer mechanism is completely independent of the medium.