Electromagnetic spectrum notes

What is the electromagnetic spectrum?

It is the range of all electromagnetic radiation wavelengths.

Radio waves

These have the longest wavelengths and are used for communication.

Microwaves

Used in cooking and certain communication technologies.

Infrared radiation

Emitted by warm objects; used in remote controls.

Visible light

The part of the spectrum that is visible to the human eye.

Ultraviolet radiation

Can cause sunburn; used in sterilization.

X-rays

Penetrate soft tissues; used in medical imaging.

Gamma rays

Have the shortest wavelength; used in cancer treatment.

Difference between UV and visible light

UV has shorter wavelengths than visible light.

Fill in the blank: The speed of light is __________.

Approximately $\displaystyle 299,792,458$ meters per second.

True or false: X-rays are safe for frequent use.

False, because they can harm cells.

What is the role of frequency in the spectrum?

Higher frequency means higher energy and shorter wavelength.

Difference between infrared and microwaves

Infrared has shorter wavelengths than microwaves.

What is wavelength?

The distance between successive peaks of a wave.

True or false: Microwaves can penetrate food.

True, because they excite water molecules.

What is amplitude in waves?

The height of a wave from its rest position.