Define resolving power of an optical instrument.

What is meant by the resolving power of an optical instrument?

Resolving power of a microscope is

What is called the power of an optical instrument to produce distinctly separate image of two close objects?

Define electric power.

What do you understand by resolving power of a astronomical telescope? Write down the expression for resolving power of an astronomical telescope.

Ray optics is based on the assumption that light travels in a straight line. Diffractions observed when light propagates through small apertures/slits or around small objects disproves this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification?

Why is the inside portion of the optical instruments like camera, telescope etc. made black?

The focal lengths of the objective and the eyepiece of a compound microscope are 4mm and 25 mm respectively . The length of the tube of the instrument is 16 cm . If the final image is formed at infinity and the least distance of distinct vision is 25 cm , determine the magnifying power of the instrument .