A plano-convex lens (focal length f2, refractive index $\mu $2, radius of curvature R) fits exactly into a plano-concave lens (focal length f1, refractive index $\mu $1, radius of curvature R). Their plane surfaces are parallel to each other. Then, the focal length of the combination will be :

Question

A plano-convex lens (focal length f₂, refractive index $\mu $₂, radius of curvature R) fits exactly into a plano-concave lens (focal length f₁, refractive index $\mu $₁, radius of curvature R). Their plane surfaces are parallel to each other. Then, the focal length of the combination will be :

f₁ + f₂

f₁ $-$ f₂

${R \over {{\mu _2} - {\mu _1}}}$

${{2{f_1}{f_2}} \over {{f_1} + {f_2}}}$

Solution

Please login to view the detailed solution steps...

Go to DASH