Electromagnetic waves
principle · 1888 · Electric age
Propagating oscillations of the electromagnetic field; proved experimentally by Hertz.
Author: Heinrich Hertz.
Principles and materials it uses
- Maxwell’s equations — uses. Predicted by Maxwell.
Where it is used
- Radio — is used in. The signal is carried by electromagnetic waves.
- Mobile phone — is used in. Communication with the base station is by radio.
- Radio module and antenna — is used in. The antenna emits and receives radio waves.
- Radar — is used in. Radio waves reflect off the target.
- GPS (satellite navigation) — is used in. Radio signals.
- Wi-Fi — is used in. Radio waves at 2.4 and 5 GHz.
- Bluetooth — is used in. Radio.
- Amplitude and frequency modulation — is used in. The carrier wave is modulated.
- Antenna — is used in. It emits and receives waves.
- Magnetron — is used in. It emits microwaves.
- Dielectric heating — is used in. An alternating field.
- Nuclear magnetic resonance — is used in. Radio pulses.
- Radar-absorbing material — is used in. Absorption.
- Car radio — is used in. It receives radio waves.
History: what it evolved from and what it influenced
- Electromagnetic induction — evolved from. Maxwell’s equations, which generalized induction, predicted electromagnetic waves.
What it is a kind of
- X-rays — includes. Short-wave electromagnetic radiation.
- Ultraviolet — includes. Electromagnetic radiation.
- Wave theory — is a kind of. Waves.
- Infrared radiation — includes. Infrared is electromagnetic waves a little longer than red light; we feel it as warmth.