Question

The distance between the objective and eyepiece lenses in a microscope is 19 cm . The objective lens has a focal length of 5.5 mm. What eyepiece focal length will give the microscope an overall angular magnification of 200?

Answer 1

The focal length of eyepiece is 3.68 cm.

Step-by-step explanation:

Given that,

Distance = 19 cm

Focal length = 5.5 mm

Magnification = 200

Object distance = -25 cm

We need to calculate the focal length

Using formula of magnification

`m=(d)/(f_(o))+(-25)/(f_(0)f_(e))`

Put the value into the formula

`f_(e)=(19*(-25))/(.55(-200-(19)/(.55)))`

`f_(e)=3.68\ cm`

Hence, The focal length of eyepiece is 3.68 cm.