A magnetic field is created when electric current flows. The greater the current the stronger the magnetic field.
- A magnetic field is created when an electric current flows, and its strength is proportional to the amount of current.
- An electric field is created by a difference in voltage between two points, and its strength is proportional to the voltage difference.
- An electromagnetic wave is created by the oscillation of electric and magnetic fields perpendicular to each other.
- An electromagnetic wave can be produced when a changing electric field generates a magnetic field, or a changing magnetic field generates an electric field.
- The waveform, wavelength and frequency of an electromagnetic wave are determined by the rate of oscillation of the electric and magnetic fields.
- When electric and magnetic fields come into contact to form electromagnetic waves they oscillate at right angles to one another.
- The direction of propagation of an electromagnetic wave is perpendicular to (at right angles to) the electric and magnetic fields.
- Electromagnetic waves propagate at a constant speed of 299,792,458 metres per second in a vacuum, which is the speed of light.
- Once an electromagnetic wave is propagating, it can be deflected by an external electric or magnetic field.
- The deflection of an electromagnetic wave is caused by the interaction between the wave and the external field, which alters the direction and speed of the wave’s propagation.
- The degree of deflection depends on various factors, such as the frequency and intensity of the wave and the strength and orientation of the external field.
- The phenomenon of deflection is known as electromagnetic scattering
Related diagrams
Each diagram below can be viewed on its own page with a full explanation.
A magnetic field is created when electric current flows. The greater the current the stronger the magnetic field.
- Whilst an electric field is created by a change in voltage (charge), a magnetic field is created when electric current flows. The greater the current the stronger the magnetic field.
- An electromagnetic wave is the result of the interaction of an electric and magnetic field because an electric field induces a magnetic field and a magnetic field induces an electric field.
- An electromagnetic wave can be induced when either the charge of an electric field changes or when the current of a magnetic field changes or when they both change together.
- The waveform, wavelength and frequency of an electromagnetic wave result from the rapid periodic succession of transitions between the electrical and magnetic components and the forward propagation of the wave through space.
- When electric and magnetic fields come into contact to form electromagnetic waves they oscillate at right angles to one another.
- The direction of propagation of an electromagnetic wave is at right angles to the electric and magnetic fields.