Focal length of a concave mirror is
(a) negative (b) positive (c) depends on the position of object (d) depends on the position of image
(a) negative
Explanation
The focal length of a concave mirror is negative because the focus of a concave mirror is in front of the mirror, on the left side.
Whereas,
The focal length of a convex mirror is positive because the focus of a convex mirror is behind the mirror, on the right side.
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