College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 62

If you increase the aperture diameter of a camera by a factor of 3, how is the intensity of the light striking the film affected (a) It increases by a factor of 3. (b) It decreases by a factor of 3. (c) It increases by a factor of 9. (d) It decreases by a factor of 9. (e) Increasing the aperture doesn't affect the intensity.