Microwaves are primarily used for which purpose?

• A. Radar operations
• B. Heating food
• C. Moon landing
• D. Optical communication

Answer: (B)

Microwaves heat food by exciting water and other polar molecules inside the food. The alternating electric field of the microwave causes these molecules to rotate rapidly, and the friction from that motion turns electromagnetic energy into heat throughout the food. That dielectric heating is the practical, everyday use of microwaves, which is why microwave ovens can cook quickly and more evenly from the inside.

Radar operations do use microwaves, but as a specialized sensing technology rather than the typical purpose people associate with microwaves. Moon-landing technology involved many systems, including communications, but the primary role of microwaves isn’t that mission’s defining function. Optical communication uses light outside the microwave range (visible/infrared), not microwaves.