The frequency of a wave means the number of oscillations occurring per second, which is the same as the number of waves arriving per second.

Radio waves, microwaves, infrared and visible light are non–ionising electromagnetic waves, as they cannot remove electrons from atoms.

Any process that transfers energy because of a temperature difference, or causes a temperature rise, can be called heating.

Oscillations are the vibrations of a wave about a rest position.

An antenna is a metal structure designed to emit or absorb electromagnetic waves.

Non-ionising electromagnetic radiations

Physics

In A-level physics, some pupils will build on this knowledge to learn about the photon model of electromagnetic radiation and the use of electromagnetic radiation for collecting evidence about the universe or for generating images of the inside of a human body.

In the Measuring waves unit, pupils learnt about the measurable features of a wave, the relationship between them and the wave equation.

Electromagnetic waves

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It cannot change the number of electrons an atom has.

Some types of electromagnetic radiation are non-ionising.
Which of the following statements about non-ionising radiation are correct?

The vibrations of a wave about a rest position.

Changes in the frequency of a wave over time.

Changes in the charge on an atom when it loses or gains electrons.

Which of the following is a definition of ‘oscillations’?

Which of the following types of radiation is used to communicate between Earth and satellites?

Four types of electromagnetic radiation are: radio waves, microwaves, infrared waves, visible light.
How many of these can harm humans, if the intensity is high enough?

They can bend around large objects, such as hills.

The direction in which they travel cannot be changed.

Lower frequency radio waves and higher frequency radio waves can both be used for long-distance communication. Which of the following describe features of lower frequency radio waves?

Alternating current causes oscillations of electrons in an aerial.

The oscillations of electrons produces radio waves.

The radio waves are absorbed by an aerial.

Electrons oscillate in an aerial, causing oscillations in an electric circuit.

Electronics convert the signal to produce sound.

Sort the following steps into the correct order to describe the process of sending and receiving a radio signal.

The wave’s energy is absorbed by the medium.

Which of the following happens when a wave is transmitted by a medium?

The {{}} of a wave is the number of wavelengths per second passing a point.

Which of the following are examples of ionisation?

Which of the following types of electromagnetic radiation has the longest wavelengths?

Which of the following types of electromagnetic radiation can cause ionisation?

At longer wavelengths, there is more energy per ‘packet’ of radiation.

At higher frequencies, there is more energy per ‘packet’ of radiation.

At shorter wavelengths, there is less energy per ‘packet’ of radiation.

At lower frequencies, there is more energy per ‘packet’ of radiation.

Why are some types of electromagnetic radiation more ionising than others?

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