A person can see clearly only up to a distanc | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) The person is suffering from myopia (nearsightedness) as he cannot see objects beyond $25 \, cm$. To correct this,a concave lens is required.Given

Vedclass · Accepted Answer

Concave,$-2.0 \, D$

Vedclass · Answer

(C) The person is suffering from myopia (nearsightedness) as he cannot see objects beyond $25 \, cm$. To correct this,a concave lens is required.Given:Object distance $u = -50 \, cm$ (the position where he wants to read).Image distance $v = -25 \, cm$ (his far point,where the virtual image must be formed).Using the lens formula: $\frac{1}{f} = \frac{1}{v} - \frac{1}{u}$$\frac{1}{f} = \frac{1}{-25} - \frac{1}{-50} = -\frac{2}{50} + \frac{1}{50} = -\frac{1}{50}$So,$f = -50 \, cm = -0.5 \, m$.The power of the lens is $P = \frac{1}{f(m)} = \frac{1}{-0.5} = -2.0 \, D$.Thus,a concave lens of power $-2.0 \, D$ is required.

$A$ person can see clearly only up to a distance of $25 \, cm$. He wants to read a book placed at a distance of $50 \, cm$. What kind of lens does he require for his spectacles and what must be its power?

Similar Questions

The far point of a myopic eye is $250 \, cm$. What is the focal length of the lens required to correct this defect?

$A$ person who can see things most clearly at a distance of $10 \, cm$ requires spectacles to enable him to see clearly things at a distance of $30 \, cm$. What should be the focal length of the spectacles?

To remove myopia (short-sightedness),a lens of power $0.66 \, D$ is required. The far point of the eye is approximately ....... $cm$.

The sensation of vision in the retina is carried to the brain by

The far point of a myopic person is $80\, cm$ in front of the eye. What is the power of the lens required to enable him to see very distant objects clearly?

Vedclass Test Series

Exam Paper Generator

Online Exam Module