The diameter of the sun is 1.4 x 109 m and its distance from the earth is 1.5 x 1011 m. Find the radius of the image of the sun formed by a lens of focal length 20 cm.

It is given that,

Diameter of the sun= 1.4 x 109 m

Distance between Earth and sun, u=1.5 x 1011 m

Focal length of the lens, f = 20cm

Using lens formula,

We know that magnification m is given by,