For a simple microscope prove that magnification `m=1+D//f`.

For a compound microscope prove that magnification is multiplied.

A convex lens of focal length 6.25cm is used as a simple microscope. To obtain maximum magnification, the object distance should be

Prove that F = ma.

Draw a ray diagram to show the formation of final image by a compound microscope. Find an expression for magnification of an image formed by a compound microscope.

A compound microscope has a magnification of 30. The focal length of its eye piece is 5 cm. Assuming the final image to be formed at near point, calculate the magnification produced by the objective.

A student measures the thickness of a human hair by looking at it through a microscope of magnification 100. He makes 20 observations and finds that the average width of the hair in the field of view of the microscope is 3.5 mm. What is the estimate on the thickness of hair?