3. (a) What is the focal length of a standard 20x microscope objective? (Assume the standard tube length of 160 mm) (b) What is the distance in air between the objective lens and the object? (c) A 10x eyepiece is used; what is its focal length? (d) What is the total magnification? (e) What is the total separation between objective and eyepiece? (f) The field stop diameter is 20 mm, therefore what is the size of the entrance window? (g) Sketch a ray diagram of the microscope configuration.

Fig: 1