Question

For a person with a Near Point (NP) = 45 cm, what would be his prescription's lens power = _________ diopters A) 1.08 diopters B) 2.842105 diopters C) 1.778 diopters D) 0.54 diopters E) 0.225 diopters

Answer 1

The power of lens is 2.22 D.

Step-by-step explanation:

Given that,

Distance of image v= 45 cm

We know that,

Distance of object u= ∞

Power of lens is the reciprocal of focal length.

`P=(1)/(f)`

We need to calculate the power of lens

Using formula of lens

`(1)/(f)=(1)/(v)+(1)/(u)`

Where, f = focal length

v = image distance

u = object distance

Put the value into the formula

`(1)/(f)=(1)/(45)+(1)/(\infty)`

`(1)/(f)=(1)/(0.45)+0`

`P=(1)/(f)=2.22`

Hence, The power of lens is 2.22 D.