Question

A geneticist looks through a microscope to determine the phenotype of a fruit fly. The microscope is set to an overall magnification of 400x with an objective lens that has a focal length of 0.60 cm. The distance between the eyepiece and objective lenses is 16 cm. Find the focal length of the eyepiece lens assuming a near point of 25 cm (the closest an object can be and still be seen in focus).

Answer 1

`f_e = 1.51 cm`

Step-by-step explanation:

given.

magnification(m) = 400 x

focal length (f_0)= 0.6 cm

distance between eyepiece and lens (L)= 16 cm

Near point (N) = 25 cm

focal length of the eyepiece (f_e)= ?

using equation

`m = -(L-f_e)/(f_o).(N)/(f_e)`

`400 = (16-f_e)/(0.6).(25)/(f_e)`

`9.6 = (16-f_e)/(f_e)`

`9.6f_e = 16-f_e`

`10.6 f_e = 16`

`f_e = 1.51 cm`