Question

Resolving power of a telescope will be more, if the diameter a of the objective is

• A. larger
• B. smaller
• C. resolving power does not depend upon a
• D. None of these

Answer 1

The correct option is A

larger

The explanation for the correct option:

In case of option A:

1. The resolving power of an objective lens is measured by its ability to differentiate two lines or points in an object. The greater the resolving power, the smaller the minimum distance between two lines or points that can still be distinguished.
2. Resolution power $=\frac{a}{1.22\lambda }$, where $\lambda =$wavelength and $a=$diameter.
3. Resolution power is directly proportional to $a$.

Hence option A is the correct answer.