BPSC – Combined Competitive Examination · ప్రశ్న 127
The focal length of a plane mirror is:
సమాధానం చూపించు & వివరణ
సమాధానం: (D) Infinity
వివరణ
A plane mirror can be seen as a sphere of infinite radius, so its focal length is infinite.
- (A) తప్పు
Wrong: a plane mirror has no finite focus.
- (B) తప్పు
Wrong: a plane mirror has no finite focus.
- (C) తప్పు
Wrong: a plane mirror has no finite focus.
- (D) సరైనది
Correct: its radius of curvature is infinite, so f = R/2 is infinite.