Electromagnetic waves

Definition

Electromagnetic waves are waves of electric and magnetic fields that propagate through space at the speed of light. They do not require a medium to travel and can move through a vacuum.

5 Must Know Facts For Your Next Test

1. Electromagnetic waves are transverse waves, meaning their oscillations are perpendicular to the direction of wave propagation.
2. The speed of electromagnetic waves in a vacuum is approximately $3 \times 10^8$ meters per second (the speed of light).
3. Electromagnetic waves can be described by their wavelength, frequency, and amplitude.
4. The electromagnetic spectrum includes radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.
5. Maxwell's equations describe how electric and magnetic fields generate and propagate electromagnetic waves.

Review Questions

• What is the relationship between the electric field and magnetic field in an electromagnetic wave?
• How do electromagnetic waves differ from mechanical waves in terms of their requirement for a medium?
• List three types of electromagnetic radiation found in the electromagnetic spectrum.

Related terms

Wavelength:

The distance between successive crests or troughs in a wave.

Frequency:

$\text{Frequency}$ refers to the number of cycles (oscillations) that occur per unit time in a wave.

Amplitude:

$\text{Amplitude}$ is the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.