Question

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

Answer 1

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