(a) Define the following terms in the context of spherical mirrors:

i) Pole

ii) Centre of curvature

iii) Principal axis

iv) Principal focus

b) Draw ray diagrams to show the principal focus of a 

i) concave mirror
ii) convex mirror

c) Consider the following diagram in which M is a mirror and P is an object and Q is its magnified image formed by the mirror. 



State the type of mirror and one characteristic property of the image Q. 

a) 
i) Pole: A pole is the central point of the reflecting surface of a spherical mirror. Pole lies on the mirror and is denoted by P. 
ii) Centre of curvature: The centre of a sphere from which the given spherical mirror (convex or concave) is obtained is called as centre of curvature. 
It is denoted by the letter C. 
iii) Principal axis: An imaginary straight line passing through the pole and centre of curvature is termed as the principal axis. 
iv) Principal focus: The focus (F) is the point on the principal axis of a spherical mirror where all the incident rays parallel to the principal axis meet or appear to diverge from after reflection. 
b) 
Concave mirror: The focus lies on the same side of the reflecting surface. 

Convex mirror: Focus is obtained on the opposite side of the reflecting surface by extending the rays reflected from the surface of the mirror.