- A change in an electric field induces a change in the magnetic field.
- A change in a magnetic field induces a change in the electric field.
- An electromagnetic wave is the result of the interaction of electric and magnetic fields.
- An electromagnetic wave can be propagated when either the charge of an electric field changes or when the current of a magnetic field changes.
- When changes in electric and magnetic fields result in electromagnetic waves, they produce synchronised oscillations that travel at right angles to one another.
- The velocity at which electromagnetic waves propagate in a vacuum is the speed of light which is 300,000 kilometres per second.
- Once an electromagnetic wave propagates outward it cannot be deflected by an external electric or magnetic field.
- The reason an electromagnetic wave does not need a medium to propagate through is because the only thing that is waving/oscillating is the value of the electric and magnetic fields.