Video Transcript
For any spherical mirror, the
distance between the center of curvature and the center of the surface is just the
radius of that sphere. Which one of the following
sentences correctly describes the location of the center of curvature of a concave
mirror? (A) The center of curvature of a
concave mirror will always be on the side opposite to the observer. (B) The center of curvature of a
concave mirror will always be on the same side as the observer. (C) Depending on the path of the
light rays, the center of curvature of a concave mirror can sometimes be on the side
opposite to the observer and can sometimes be on the same side as the observer.
To start figuring out which of
these three answer options is correct, let’s sketch a curved mirror. And we’ll say that this is a
concave mirror. A concave mirror is one where light
always enters into the curved portion of the mirror, here on this side. This is the opposite of light being
incident on the mirror from this side. All of our possible answers talk
about which side of a concave mirror an observer will be on. In order to observe or see the way
a concave mirror reflects light, an observer always needs to be on the same side of
the mirror as the incoming rays of light. An observer of a concave mirror
then is always facing this curve of the mirror shape.
We can recall that this shape is
part of a larger circle. The center of that circle, located
here, is called the center of curvature of the mirror. For a concave mirror then, the
center of curvature of the mirror and an observer are always on the same side of the
mirror. What we’re finding is that answer
option (B) is the correct description of a concave mirror. The center of curvature of a
concave mirror will always be on the same side as the observer.
