Question

if the focal length of a spherical mirror is + 20 cm , then which type of spherical mirror is it ?

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Answer 1

It is a convex mirror.

Answer 2

It's a concave mirror.

• There are two types of spherical mirrors.

1. Concave mirror
2. Convex mirror

• The focal length of the concave mirror has a positive magnitude whereas the focal length of the convex mirror has a negative magnitude.
• As, the focal length given in the question has a positive magnitude, so it will be definitely a concave mirror.