Question

Which of the following statements about light focusing is not true?

A) In a healthy eye, light is focused on the retina.
B) Film should be placed at the focal plane in a camera.
C) If you try to look at an image that is not formed at the focal plane, it will be blurry.
D) The focal plane of a reflecting telescope is always located within a few inches of the primary mirror.
E) Light can be focused with a lens or a mirror.

Answer 1

The incorrect statement about light focusing is that the focal plane of a reflecting telescope is always within a few inches of the primary mirror; in reality, the focal plane can be elsewhere, depending on the telescope design.

Step-by-step explanation:

The statement about light focusing that is not true is D) The focal plane of a reflecting telescope is always located within a few inches of the primary mirror. In reflecting telescopes, the focal plane is not restricted to be within a few inches of the primary mirror. Rather, the mirror reflects light to form an image near the front end at a location called the prime focus, and additional optics can be used to change the path and location of this focal plane. Also, for nearsighted individuals, the focal points are incorrectly stated to be between the lens and the retina. The correct statement is that a nearsighted person has eyes with focal points in front of the retina, while a farsighted person has eyes with focal points beyond the retina.