Multiple choice

The mode of propagation of heat from the sun to the earth is

  1. conduction

  2. convection alone

  3. radiation alone

  4. convection and radiation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sun and earth are separated by vacuum (space). Heat cannot be transferred by conduction (requires medium) or convection (requires fluid medium) in vacuum. The only mode of heat transfer possible through vacuum is radiation, which travels as electromagnetic waves (infrared, visible light). Therefore, heat from sun reaches earth by radiation alone.

Keep practicing — related questions