19 questions · timed · auto-graded
The laws of reflection holds good for light reflected form any smooth surface i.e., all mirrors regardless of its shape.
$\text{m}=\frac{\text{h}'}{\text{h}}=\frac{-\text{v}}{\text{u}}\text{ or}$
$\text{u}=\frac{-\text{v}\times\text{h}}{\text{h}'}=\frac{-(-30\text{cm})\times(10\text{mm})}{-5\text{mm}}$
$=-60\text{cm}$
$\therefore\ \frac{1}{\text{f}}=\frac{1}{\text{u}}+\frac{1}{\text{v}}=-\frac{1}{60}-\frac{1}{30}=-\frac{1}{20}$
$\text{or f }=-20\text{cm}.$
$\text{n}_{\text{BA}}=\frac{\sin\text{i}}{\sin\text{r}}=\frac{\sin60^\circ}{\sin45^\circ}$
$=\frac{\frac{\sqrt{3}}{2}}{\frac{1}{\sqrt{2}}}=\frac{\sqrt{3}}{\sqrt{2}}$
In convex lens, the incident ray passing through F goes parallel to the principal axis after refraction.
