Question

What is meant by the resolution of a telescope?

Answer 1

Hint: As a first step, you could briefly explain what the angular resolution of an optical device is and then you could specify it in the case of a telescope. You could then explain the limitations for this quantity. You could also explain the term for the case of other optical instruments and hence answer the question.

Complete step-by-step solution:
In the question we are asked to define the resolution of a telescope. The basic definition of resolution of a telescope goes like this. The smallest angle between two close objects that makes them clearly visible separately is called the angular resolving power which is otherwise known as ‘resolution’ of a telescope. The wave nature of light does act as a limitation to the resolution of a telescope. Also, it is also a known fact that the resolving power of a telescope is directly proportional to the ratio of light’s wavelength to the diameter of the telescope.
The term angular resolution basically applies to all optical instruments, be it a microscope, a camera, a telescope or even an eye. It is simply their ability to distinguish between small objects or even small details of an object.

 Note: Now for the case of diffraction limited resolution, it could be defined by the Rayleigh criterion which defines it as the angular separation that exists between two point sources. But, we have a condition here: the maximum of these sources lies in the first minimum of the diffraction pattern so observed.