physics chapter 1- reflection of light at curved surfaces

Law of Reflection

The angle of incidence is equal to the angle of reflection; it holds true for all surfaces.

Normal Line

A line perpendicular to the surface at the point of incidence.

Centre of Curvature (C)

The center of the sphere from which the mirror is a part; all normals converge toward this point in a concave mirror.

Pole (P) of the mirror

The midpoint of the mirror where the principal axis intersects the mirror surface.

Principal Axis

A horizontal line that passes through the centre of curvature and the pole of the mirror.

Radius of Curvature (R)

The distance from the pole of the mirror to the centre of curvature, given as R = 2f, where f is the focal length.

Focus (F) of a concave mirror

The point where parallel rays of light converge after reflecting off the concave mirror.

Focal Length (f)

The distance from the pole to the focal point; for a concave mirror, it is considered negative in sign convention.

Virtual Image

An image that cannot be projected on a screen, appears erect and can be seen when looking into the mirror.

Real Image

An image that can be projected on a screen, appears inverted and is formed when light rays actually converge.

Magnification

The ratio of the height of the image to the height of the object, also defined as m = -v/u.

Convex Mirror

A mirror that bulges outward, causing parallel rays to diverge and appear to come from a virtual focus behind the mirror.

Concave Mirror

A mirror that curves inward, where parallel rays converge at a focal point in front of the mirror.

Mirror Formula

The relationship between object distance (u), image distance (v), and focal length (f) given as 1/f = 1/v + 1/u.

Sign Convention

A set of rules for measuring distances in optics: distances measured in the direction of incident light are positive, and those in the opposite direction are negative.

Ray Diagrams

Diagrams used to trace the path of light rays as they interact with a mirror to determine the nature and position of images.

Activity: Finding the normal to a curved surface

A practical activity using foam or rubber to demonstrate finding normals and understanding angles of incidence and reflection.

Experiment with Sun Rays

An experiment to find the focal point of a concave mirror using sunlight to measure the focal length.

Image Formation in Convex Mirrors

In a convex mirror, rays parallel to the principal axis appear to diverge from the focal point, producing a virtual, erect image.