NEET2016PhysicsRay OpticsActual
A person can see clearly object only when they lie between 50 cm to 400 cm from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be
Options
- AConvex, + 2 . 25   D
- BConcave, - 0 . 25   D
- CConcave, - 0 . 2   D
- DConvex, +   0 . 15   D
Correct answer
B. Concave, - 0 . 25   D
Step-by-step solution
The maximum distance of distinct vision = 400   cm . So the image of the object at infinity is to be formed at 400   cm . Use lens formula 1 v - 1 u = 1 f 1 - 400 - 1 ∞ = 1 f P = - 0.25   D