Saved Bookmarks
| 1. |
A convex and a lens separated by distane d are then put in contact. The focal length of the combination |
|
Answer» Becomes 0 `(1)/(F)=(1)/(f_(1))+(1)/(f_(2))-(d)/(f_(1)f_(2))` As `f_(2)` is negative, `(1)/(F_(1)) = (1)/(f_(1)) - (1)/(f_(2)) + (d)/(f_(1)f_(2))` When put TOGETHER, `(1)/(F_(2)) = (1)/(f_(1)) - (1)/(f_(2))` `therefore F_(1) = (f_(1)f_(2))/(f_(2) - f_(1) + d) ,F_(2) = (f_(1)f_(2))/(f_(2) - f_(1))` Therefore the focal lenght for this combination, become LARGER. If `f_(1) = f_(2)`, this combination GIVES infinity in contact and not zero. Therefore for the option given different focal lenght are assumed. |
|