Question

A lens has a radius of curvature of magnitude R R on its left surface and a radius of curvature of magnitude 2R 2 R on its right surface. Parallel rays entering the lens from the left are focused to a point 145 mm m m to the right of the right surface.

Answer 1

`v=-29cm`

Step-by-step explanation:

From the question we are told that:

Radius
`R=2f`

Distance
`v=145mm=>14.5cm`

Generally the equation for is mathematically given by

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

Therefore

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

`(1)/(f)=(1)/(14.5)`

`f=14.5cm`

Therefore

`R=2f\\\\R=2*14.5`

`R=29cm`

Generally the equation for Focal Length of the Right surface is mathematically given by

`f_r=(R_r)/(2)`

`f_r=(2R)/(2)`

`f_r=29cm`

Therefore

`(1)/(29)-(1)/(14.5)=(1)/(v)`

`(1)/(v)=-(1)/(29)cm`

`v=-29cm`