NEET2008PhysicsRay OpticsActual
A boy is trying to start a fire by focusing sunlight on a piece of paper using an equiconvex lens of focal length 10 ~cm . The diameter of the sun is 1.39 10^9 ~m and its mean distance from the earth is 1.5 10¹¹ ~m . What is the diameter of the sun's image on the paper?
Options
- A9.2 10⁻⁴ ~m
- B6.5 10⁻⁴ ~m
- C6.5 10⁻⁵ ~m
- D12.4 10⁻⁴ ~m
Correct answer
A. 9.2 10⁻⁴ ~m
Step-by-step solution
From the relation I O = v u Here, O=1.39 10^9, v=0.1 ~m , aligned u & =1.5 10¹¹ ~m I & = 0.1 1.5 10¹¹ 1.39 10^9 & =9.2 10⁻⁴ ~m aligned