BPSC – Combined Competitive Examination · પ્રશ્ન 127
The focal length of a plane mirror is:
જવાબ બતાવો અને સમજૂતી
જવાબ: (D) Infinity
સમજૂતી
A plane mirror can be seen as a sphere of infinite radius, so its focal length is infinite.
- (A) ખોટો
Wrong: a plane mirror has no finite focus.
- (B) ખોટો
Wrong: a plane mirror has no finite focus.
- (C) ખોટો
Wrong: a plane mirror has no finite focus.
- (D) સાચો
Correct: its radius of curvature is infinite, so f = R/2 is infinite.