Question

The sun is just covered by a disc of 2cm diameter placed about 2m from the eye. If the length of the diameter of the sun's image formed by a pin-hole camera is 0.5cm. Calculate the distance from the pin-hole to the screen

Answer 1

$\frac Hh=\frac fd,$

$d=\frac{hf}H=\frac{0.5\cdot 2}{2}=0.5~m.$