Question

The ratio of the diameter of the Sun to the distance between the earth and the Sun is approximately $\mathrm{0.0093.}$ Image of the Sun is formed using a concave mirror of radius of curvature $4m$. Diameter of the image of the Sun will be ______cm.

Answer 1

Answer: 1.86

From geometry of given figure,
$\theta =\frac{D}{x}=\frac{d}{f}$
$\therefore d=\frac{D}{x}\times f=\frac{D}{x}\times \frac{R}{2}$
$\dots .(R=$ radius of curvature of mirror $)$
$\therefore d=0.0093\times 2\dots .\left(\text{ Given: }\frac{D}{x}=0.0093\right)$
$=0.0186m$
$=1.86cm$