Search SchoolNGR

Saturday, 07 March 2026
Register . Login

A certain far - sighted person cannot see object that are closer to the eye than 50 cm ...

A certain far - sighted person cannot see object that are closer to the eye than 50 cm clearly. Determine the power of the converging lens which will enable him to see at 25 cm
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
  • A 0.06 D
  • B 0.02 D
  • C 0.03 D
  • D 0.04 D
  • E No option is correct
Correct Answer: Option E
Explanation:
V = - 50, U = 25CM
(1)/r = (1)/v + (1)/u = (1)/-50 + (1)/25 = (1 + 2)/50 = (1)/50 f = +50cm = +0.5m
p = (1)/r = (1)/0.5 = (10)/5 = 2 diopters
The power of a lens is the reciprocal of the focal length in meters. it is expressed in diopters.

Share question on: