A small bulb is placed at the focus of a concave mirror of focal length 12 cm. The reflected beam is
Aa parallel beam
Ba converging beam to 12 cm
Ca diverging beam
Dfocused at 24 cm
Answer & Solution
Correct answer: A. a parallel beam
Rays from an object at the focus reflect parallel to the principal axis — this is the principle of searchlights and headlamps.
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