Home
Class 12
PHYSICS
The near and far poit sof a person are t...

The near and far poit sof a person are t 40 cm and 250 cm respectively. Find the power of thlens he /she should use while reading at 25 cm. with this lens on the eye, what maxmum distance is cleary visible?

Text Solution

Verified by Experts

If an object is placed at 25 cm from the correcting lens, it should produce the virtual image at 40 cm. Thus,
`u=-25cm,v=-40,1/f=1/v-1/u=-1/(40cm)+1/(25cm)`
or, `f=200/3cm=+2/3morP=1/f=+1.5D`
The unaided eye can see a maximum distance of 250 cm. Suppose the maximum distance for clear vision is d when the lens is used. Then the object at a distance d is imaged by the lens at 250 cm. We have,
`1/v-1/u=1/for-1/(250cm)-1/d=3/(200cm)ord=-53cm`
Thus, the person will be able to see upto a maximum distance of 53 cm.
Promotional Banner

Similar Questions

Explore conceptually related problems

The near and far points of a person are at 40 cm and 250cm respectively. Find the power of the lens he/she should use while reading at 25cm . With this lens on the eye, what maximum distance is clearly visible?

The near point and far point of a person are 40cm and 250cm, respectively. Determine the power of lens he/she should use while reading a bool kept at distance 25cm away from it,

The near point and the far point of a child are at 10 cm and 100 cm. If the retina is 2.0 cm behind the eye-lens, what is the range of the power of the eye-lens?

If a person can sees clearly at a distance of 100 cm, then find the power of leris used to see object at 40 cm.

A nearsighted person cannot clearly see beyond 200 cm. Find the power of the lens needed to see objects at large distances.

In a morning walk, three persons step off together and their steps measure 40 cm, 42 cm and 45cm, respectively. What is the minimum distance each should walk so that each can cover thesame distance in complete steps?

In a morning walk, three persons step off together and their steps measure 40 cm, 42 cm and 45cm, respectively. What is the minimum distance each should walk so that each can cover thesame distance in complete steps?

For a person near point of vision is 100cm. Then the power of lens he must wear so as to have normal vision, should be

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

In a morning walk, three persons step off together. Their steps Measure 80 cm, 85 cm and 90 cm respectively. What is the minimum distance each should walk so that all can cover the same distance in complete steps?