Chapter 6, Problem 1QP

To determine

The correct statement about the telescopes having different aperture size.

Answer to Problem 1QP

Option (c)

Explanation of Solution

Light gathering power of a telescope is proportional to the square of aperture.

    $P\sim \pi {\left(\frac{D}{2}\right)}^2$

Here, $P$ is the light gathering power of a telescope and D is the aperture size.

Conclusion:

The equation shows that higher the aperture size, higher will be the light gathering power. Thus, option (c) is correct.

20 cm telescope will have less gathering power. Thus, option (a) is incorrect.

Image size is not related to aperture size. Thus, option (b) and (d) are incorrect.