why are mirrors used in search lights parabolic and not concave spherical?

Asked by thajvirkaur | 30th Jan, 2012, 08:10: AM

Expert Answer:

A search light produces an intense parallel beam of light.This requires a reflector of large aperture.When a sourceis placed at the focus of a large concave mirror only the paraxial rays (not the marginal rays)are reflected as parallel beam. but when a source is placed at the focus of parabolic mirror all the rays are reflected  as an intense parallel beam

Answered by  | 30th Jan, 2012, 09:25: AM

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