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Photoelectric Effect

Key Stage 3

Meaning

A photoelectric effect is when light causes an electrical current.

About the Photoelectric Effect

Light transfers energy which can be absorbed by a material causing electrons to gain energy and move.
The photoelectric effect is used in digital cameras to make a picture. The light is focused through a lens onto a detector which generates an electrical current depending on the intensity of light.

Key Stage 4

Meaning

A photoelectric effect is when light causes an electrical current.

About the Photoelectric Effect

Light transfers energy which can be absorbed by a material causing electrons to gain energy and move.
The photoelectric effect is used in digital cameras to make a picture. The light is focused through a lens onto a detector which generates an electrical current depending on the intensity of light.

Key Stage 5

Meaning

A photoelectric effect is a phenomenon in which electrons are emitted form the surface of a metal when light of a minimum 'threshold' frequency is incident upon its surface.

About the Photoelectric Effect

The Photoelectric Effect is proof of the photon model of light.
The emission of photoelectrons depends upon the frequency of light incident upon a metal's surface. Below the threshold frequency there are no photoelectrons emitted.
Below the threshold frequency the intensity of the light has no effect on the emission of photoelectrons (none are emitted). However, above the threshold frequency an increase in the intensity of light will increase the number of photoelectrons emitted, but will not affect their maximum kinetic energy.