Why are concave mirrors used in headlights?

1 Answer
Mar 15, 2018

Basically concentrate the beam: To reduce the beam width (to near parallel) so the intensity at a larger distnace from the headlight is higher.

Explanation:

Work out the light ray diagram if an object is at the focus of a concave mirror.

You will find the rays are parallel as the exit the mirror, so the light beam is parallel and all the light generated from the lamp is focussed.

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