Far point of a person is 5 m. In order that he has normal vision what ki nd of spectacles should he use?
A. concave lens with focal length 5 m
B. concave lens with focal length 10 m
C. convex lens with focal length 5 m
D. convex lens with focal length 2.5 mm
Answer:A
Far point of a person is 5 m. In order that he has normal vision what ki nd of spectacles should he use?
A. concave lens with focal length 5 m B. concave lens with focal length 10 m C. convex lens with focal length 5 m D. convex lens with focal length 2.5 mm