Question

3 a microwave heating leftovers is an example of thermal energy transfer by–
a radiation.
b induction.
c convection.
d conduction.

Explanation:

To determine the correct answer, we analyze each option:

• Option A: Radiation is the transfer of energy via electromagnetic waves (like microwaves). Microwaves use electromagnetic radiation to heat food, so this fits.
• Option B: Induction involves using magnetic fields to heat conductive materials (e.g., induction stoves), not how microwaves work.
• Option C: Convection is heat transfer by fluid (liquid/gas) movement, not relevant to microwaves.
• Option D: Conduction is heat transfer through direct contact (e.g., a pan heating food), not how microwaves heat.

Answer:

A. radiation.