What is the ratio of the light-gathering power of a 10-m telescope to that of a 1-m telescope
A)10 to 1
B)1 to 10
C)100 to 1
D)1 to 100
E)3.2 to 1

Question

Quizplus · Accepted Answer

The light-gathering power of a telescope is proportional to the area of its primary mirror or lens, which is proportional to the square of the radius. Therefore, the ratio of the light-gathering power of a 10-m telescope to that of a 1-m telescope is (10/1)^2 = 100/1 = 100 to 1. So, the best choice is C.

What Is the Ratio of the Light-Gathering Power of a 10-M