Heat transfer that does not require a medium is called:

उत्तर: (A) Radiation

• (A) बरोबर

  Correct: radiation travels as electromagnetic waves, even through vacuum.

• (B) चूक

  Wrong: not a mode of heat transfer.

• (C) चूक

  Wrong: needs a material medium (mostly solids).

• (D) चूक

  Wrong: needs a fluid medium.