A far-sighted man who has lost his spectacles reads a book by looking through a small hole in the sheet of paper. Then in doing so, the focal length of the eye lens is effectively decreased
30) A far-sighted man who has lost his spectacles reads a book by looking through a small hole in the sheet of paper. Then
Answer is:
in doing so, the focal length of the eye lens is effectively decreased
Explanation:
Related Optics MCQ with Answers
Answer is:
? = 2 R
Explanation:
A plano-convex lens is made of glass of refractive index 1.5.The focal length ? of the lens and radius of curvature R of its curved face are related as f = 2R
Answer is:
41397
Explanation:
The diopter is the unit of measure for the refractive?power?of a?lens. The?power?of alens?is defined as the reciprocal of its focal length in meters, or D = 1/f, where D is the?power?in diopters and f is the focal length in meters.?Lens?surface?power?can be found with the index of refraction and radius of curvature.
Answer is:
14.3 cm
Explanation:
M = di / do so 2.5do = di And, 1/f = 1/di + 1/do f = 25 do / 35 f = 25 * 30 / 35 = 750/35 cm = 21.4 cm