KCET2011PhysicsRay Optics
Two thin lenses have a combined power of +9D. When they are separated by a distance of 20 ~cm , their equivalent power becomes + 27 5 D. Their individual powers (in dioptre) are
Options
- A1,8
- B2,7
- C3,6
- D4,5
Correct answer
C. 3,6
Step-by-step solution
Given, gathered P₁+P₂=9 P=P₁+P₂-d P₁ P₂ 27 5 =9- 20 100 P₁ P₂ gathered Hence, the above equation is correct for P₁=3 and P₂=6 .