Question

For a person, the distance of eye lens from the retina is $2.00\text{cm}$ and maximum focal length of the eye lens is $1.96\text{cm}$. Find the far point of the person.

• A. $88\text{cm}$
• B. $98\text{cm}$
• C. $78\text{cm}$
• D. $68\text{cm}$

Answer 1

The correct option is B $98\text{cm}$

When the object is kept at the far point, its image will form on the retina.

Let the far point of the person is $x$.

So, $u=-x\text{cm}$, $v=2.00\text{cm}$ and $f=1.96\text{cm}$

Using lens formula,

$\frac{1}{f}=\frac{1}{v}-\frac{1}{u}$

$\Rightarrow \frac{1}{1.96}=\frac{1}{2.00}-\frac{1}{(-x)}$

$\Rightarrow x=98\text{cm}$

Hence, option $\left(B\right)$ is the correct answer.