BPSC – Combined Competitive Examination · प्रश्न 127
The focal length of a plane mirror is:
उत्तर दाखवा आणि स्पष्टीकरण
उत्तर: (D) Infinity
स्पष्टीकरण
A plane mirror can be seen as a sphere of infinite radius, so its focal length is infinite.
- (A) चूक
Wrong: a plane mirror has no finite focus.
- (B) चूक
Wrong: a plane mirror has no finite focus.
- (C) चूक
Wrong: a plane mirror has no finite focus.
- (D) बरोबर
Correct: its radius of curvature is infinite, so f = R/2 is infinite.