A compound microscope consists of an objective of focal length 1 cm and an eyepiece of focal length 5 cm. An object is placed at a distance of 0 5 cm from the objective. What should be the separation between the lenses so that the microscope projects an inverted real image of the object on a screen 30 cm behind the eyepiece?

Question

Philoid · Accepted Answer

Given data-

Focal length of the objective lens, f_o = 1.0 cm

Focal length of the eyepiece , f_e = 5 cm

Distance between Object and objective lens, u₀ = 0.5 cm

Distance between image and eyepiece, v_e = 30 cm

Applying lens formula for objective lens

For compound microscope, the objective lens forms a virtual image at the side same as that of the

object at a distance of 1 cm from the objective lens.

This image formed by the objective lens acts as a virtual object for the eyepiece.

Now applying lens formula for the eyepiece

Hence the Separation between the objective and the eyepiece becomes

6 − 1 = 5 cm