## Tuesday, November 10, 2009

### [Physics Form 4] Curved Mirrors

1. The two types of curved mirrors are the concave mirror and the convex mirror.

2. Terminologies associated with concave and convex mirrors:
• The pole is the centre point of the surface of the concave or convex mirror. It is symbolised as P.

• The centre of curvature is the centre of sphere in which the concave and convex mirrors are part of. It is symbolised as C.

• The radius of curvature is the distance from the pole to the centre of curvature. It is symbolsed as R.

• The principal focus point is the point in which all rays parallel to the principal axis pass through (for concave mirror) or appear to emerge from (for convex mirror), after being reflected from the respective mirrors. It is located on the principal axis and is symbolised as F.

• The focus point of a concave mirror is real, while the focus point of a convex mirror is virtual.

• The focal length is the distance between the pole and the focus point. It is symbolised as f. The focal length is half the radius of curvature; f = R/2.

• The focal length f a concave mirror is real, and denoted as +f, while that of a convex mirror is virtual, and denoted as -f.