Question

The distance of the sun form the earth is $1.5\times {10}^{11}$ and its diameter is $1.40\times {10}^{9}m.$ The diameter of the image of the sun formed by a lens of focal length $1m$ is nearly:

• A. $1\times {10}^{-4}m$
• B. $1\times {10}^{-3}m$
• C. $1\times {10}^{-2}m$
• D. $100m$

Answer 1

The correct option is C $1\times {10}^{-2}m$

$m=\frac{I}{O}=\frac{f}{u}$

$\Rightarrow I=\frac{O}{u}\times f$

$=\frac{1.4\times {10}^9}{1.5\times {10}^{11}}\times 1m$

$=1\times {10}^{-2}m.$