Question

Why don't we have a simple telescope?

• A. We have simple telescope of short range.
• B. We would need a convex lens of very huge focal length.
• C. We would need a convex lens of very small focal length.
• D. Simple telescope take a lot of time to make.
• E. None of the above

Answer 1

The correct option is B We would need a convex lens of very huge focal length.

A simple telescope will be made using just one convex lens. To form a virtually magnified image from a convex lens, the object needs to be placed within the pole and focus of the lens. This is practically not feasible as we deal with objects that are very far from the Earth and making a single convex lens of such a huge focal length is practially impossible.