Question

an object 50 cm high is placed 1 m in front of a converging lens whose focal length is 1.5 m. determine the image height (in cm).

Answer 1

Given :

An object 50 cm high is placed 1 m in front of a converging lens whose focal length is 1.5 m.

To Find :

the image height (in cm).

Solution :

By lens formula :

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

Here, u = - 100 cm

f = 150 cm

`(1)/(v) - (1)/(-100) = (1)/(150)\\\\v = - 300 \ cm`

Now, magnification is given by :

`m = (v)/(u) = (h_i)/(h_o)\\\\h_i = (300)/(100)* 1\\\\h_i = 3 \ m`

Therefore, the image height is 3 m or 300 cm.