How does a microwave work?

Answer 1

A microwave oven heats food in a process called dielectric heating. The molecules in the food, primarily water molecules, are polar molecules - meaning they have both a positive and a negative pole due to the distribution of positive and negative charges on the atoms. When they are subjected to microwaves, the molecules rotate as to align themselves with the electromagnetic field, much like a compass aligning itself with the magnetic field of the Earth. Microwave ovens alternate the electromagnetic field to reverse the polarity, causing the molecules to then rotate the other way. Using the compass analogy, imagine taking a magnet and doing circles around the compass; the needle goes crazy. This excited rotation of (mostly) water molecules generates molecular friction with other surrounding excited molecules, generating heat.

A common misconception is that the molecules have resonance with the particular frequency used by a microwave oven; ovens that use different frequencies can cook just as efficiently. Another misconception regards the safety of microwave ovens and their radiation. The radiation used in a microwave oven is in the form of radio waves; this is non-ionizing radiation, meaning it is not the same kind of radiation that can cause cancer; that kind of radiation is called ionizing radiation - sunlight and nuclear radiation are examples. Therefore, a microwave oven's radiation cannot cause cancer or other ionizing effects. It's also commonly believed that standing too close to a microwave oven can be harmful, but this is not true. A microwave oven acts like a Faraday cage; the holes in the metal grill that's visible through the oven door are essentially invisible to the radio waves, thanks to their wavelength, so most of the energy is reflected back into the oven. Other sources of microwave radiation, such as cell phones, cannot heat objects like a microwave for two reasons: The relative power of the transmission, and the fact that a microwave oven concentrates nearly all of the energy into the food, whereas a cell phone's transmissions dissipate in all directions, leaving the tiniest fractions of that energy to be absorbed by the body.
It heats up and thaws the food that you have placed in the microwave

Answer 2

You press the on button