Q. Consider the following statements regarding modes of heat transfer:

1. Conduction occurs primarily in solids due to molecular vibration and direct contact.
2. Convection occurs in liquids and gases, involving bulk movement of molecules.
3. Radiation transfers heat without requiring a physical medium, through electromagnetic waves.

Which of the above statements is/are correct?
Answer: 1, 2 and 3
Notes: All three statements regarding heat transfer are correct. Conduction predominates in solids through direct molecular interaction; convection is the main mechanism in fluids (liquids and gases) via mass movement; and radiation transfers energy via electromagnetic waves, requiring no medium, as observed with the Sun’s heat reaching Earth.