Lecture 10/26 Geometrical Optics

Question 1

Focal Length

Answer 1

The focal length tells us the angle of view—how much of the
scene will be captured—and the magnification—how large
individual elements will be. The longer the focal length, the
narrower the angle of view and the higher the magnification.

Question 2

Spherical Mirrors: Convex Mirrors

Answer 2

o A convex spherical mirror has
the silvered surface of the
mirror on the outer, or
convex, side of the curve
o A convex mirror is sometimes
called a diverging mirror

o The rays from any point on the object diverge after reflection
as though they were coming from some point behind the
mirror
o The image is virtual because it lies behind the mirror at the
point where the reflected rays appear to originate
o In general, the image formed by a convex mirror is upright,
virtual, and smaller than the object