Your Microwave Questions Answered

Questions about your microwave? We've got you covered.

Published June 17, 2019.

We answer your most frequently asked questions about microwaves.

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How Do Microwaves Work?

Microwaves employ a device called a magnetron that uses electric current and magnets to generate electromagnetic waves ("microwaves"), which create a field with a positive and negative charge. These charges reverse direction an astounding 4.9 billion times per second.

How Do Microwaves Heat Food?

Microwaves interact with water molecules and, to a lesser extent, oil. When water molecules, which have positive and negative charges, are exposed to the oscillating positive and negative charges of microwaves, they move at the same incredibly fast rate, bumping into one another (and into nearby molecules, such as fats and proteins) and increasing their temperature.

How Do Microwaves Cook Food?

Microwaves strike the exterior of food and in most cases penetrate about an inch into the interior, causing water molecules to heat up. That heat energy then transfers to adjacent molecules, heating the rest of the food via conduction.

Why Is There Mesh on the Door?

The holes allow users to see into the oven, and the metal reflects some microwaves back toward the food. The holes are small enough that microwaves can't fit through.

Why Is the Interior Metal?

Microwaves bounce off the metal surfaces, back toward the center of the oven.

Why Do Microwaves Have Turntables?

By rotating the food, the turntable helps microwaves reach—and heat—more of a food's surface.

How Does the Power Level Work?

When you lower the power level in a microwave, you decrease the amount of time the magnetron stays on. So, at 50 percent power, the microwave will emit electromagnetic waves for about 30 seconds out of a 1-minute cooking time by pulsing on and off intermittently. 

How Can I Clean My Microwave Easily?

Microwave 2 cups water at full power until steaming but not boiling, about 2 minutes. Let sit for 5 minutes. Steam will loosen dried, stuck-on food. Wipe clean.

Tips for Heating Food Efficiently in the Microwave

Stir or Flip Often

Movement allows the microwaves to hit new parts of the food and promotes heat transfer via conduction.

Cover Food

Using a plate or an inverted bowl to cover the food traps steam, which provides more cooking via conduction.

Let Food Rest

Letting food rest for a few minutes after cooking it allows hot and cool spots to even out through conduction.

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