Question

a) Will one telescope be sufficient for us to observe space completely? Why do we need different telescopes for the purpose? ​

Answer 1

Answer:

No, we cannot use only one telescope for viewing the space completely  

Explanation:

This is because we need different focal lenses for viewing the objects accordingly. An image is formed different in different sizes and focal lengths.

Also if we are on one hemisphere of earth, we cannot see the things present on other side

And the main thing is that space is really big, its bigger than your imagination.

If you didn't understand about the focal lengths, then refer to   class 10 book chapter light reflection and refraction. The chapter pdfs are available on many websites