(a)(i) Principal focus of a convex mirror is a pc.nt on the principal axis on which all rays parallel and close to the principal axis appear to diverge after reflection.
(ii) The pole is the centre of the mirror through which the principal axis pass.
(iii) Radius of curvature is the radius of the sphere from which the mirror was cut.
(b) Advantages of using convex mirror for driving
-wide field of view
-image is always upright.

Disadvantages of using convex for driving:
-image is smaller
-image appears further away and gives false impression of the distance.


(d)(i) \(\frac{1}{u} + \frac{1}{v} = \frac{1}{f}; \frac{1}{u} - \frac{1}{30} = \frac{1}{10}; \frac{1}{u} = \frac{1}{10} + \frac{1}{30}\)
= \(\frac{4}{30} = \frac{2}{15}; u = \frac{15}{2}\) = 7.5cm
(ii) \(\frac{\text{image size}}{\text{object size}} = \frac{\text{image distance x object size}}{\text{object distance}}\)
= \(\frac{30 \times 0.25}{7.5} = 1cm\)
(iii) Power = \(\frac{1}{\text{focal length (in metre)}} = \frac{1}{0.1}\)
= +10.0 dioptre 0.1