The Doppler Effect

1 mark · Easy

State whether the wavelength of waves increases or decreases in the direction a source is moving.

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The wavelength decreases (becomes shorter) in the direction a source is moving.

Also accept: Decreases; Gets shorter

Common mistakes: Saying 'increases'

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Marking points

B1 · 1 mark · States that the wavelength decreases (gets shorter) in the motion direction.

Worked solution

The wavelength of waves decreases (becomes shorter) in the direction the source is moving.