Physics in Everyday Life

How Microwaves and Conventional Ovens Work?

By: Sai Piyush Pathak - Researcher

Microwaves use electromagnetic waves to heat food. These waves interact with water molecules, which are polar, meaning they have a positive and negative side. When the microwaves hit them, they cause the water molecules to rapidly rotate, creating friction. This friction generates heat, which cooks your food quickly from the inside out.

The frequency of microwaves, about 2.45 GHz, is perfect for agitating water molecules without affecting other components too much. This is why food with more water heats faster in a microwave.

On the other hand, Conventional ovens heat food using thermal energy through two processes: convection and radiation.

• Convection happens when hot air circulates in the oven, transferring heat to the food’s surface and cooking it slowly from the outside in.

  
  

• Radiation from the heating element emits infrared waves that heat the food by causing its molecules to vibrate.

Since ovens cook from the outside in, they’re ideal for foods that need a crispy exterior, unlike microwaves, which mainly heat water-rich foods quickly.