State any one advantage of using a reflecting telescope in place of a refracting telescope.

In which, microscope or telescope, is the difference in focal lengths of the objective and the eye-piece smaller?

The resolving power of normal human eye is $1’$ (one minute). Explain its meaning.

Using a ray-diagram, show the image formation by a simple microscope (magnifying glass). What is the nature of the image?

What is the difference between linear magnification and angular magnification (also called magnifying power) produced by a lens?

Why is, in a microscope, objective lens of a small aperture is taken?

Draw ray-diagram to illustrate formation of image in a compound microscope.

Express the magnifying power (angular magnification) of an astronomical telescope in terms of the focal lengths of the objective and the eye-piece.