Saved Bookmarks
| 1. |
A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices y, and y, and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is ...... |
|
Answer» `(R)/(2(mu_1+mu_2))` but `f_1=(R)/(mu_1-1)` and `f_2=-(R)/(mu_2-1)` `THEREFORE 1/f=((mu_1-1))/(R)-((mu_2-1))/(R)` `therefore 1/f=([mu_1-1-mu_2+1])/(R)=((mu_1-mu_2))/(R)` `therefore f=(R)/((mu_1-mu_2))` |
|