How does decrease in curvature increase the focal length of the lens?
Dear student,
Curvature is defined as a lens inability to be flat, or the degree to which a lens curves. Now, lets think about this. A lens curvature represents a part of a circle. If you increase the curvature, in other words, curve the lense more, that would make the circle smaller. A radius is the distance from the center of the circle to the outside of the circle. So if you effectively make the circle smaller, you also decrease the radius of the circle. This is sort of tricky, what is known as an inverse or indirect relationship. If we increase the amount of curvature, we get a decrease in the amount of curvature radius. Or, we could go the other way, if we decrease the amount of curvature, we get an increase in the amount of curvature radius. In any event, when one factor moves, the other factor goes in an opposite direction. So, the bottom line is, increasing the curvature of the lens would decrease the radius of curvature.
We know that f=R/2
So on decreasing the curvature, the radius of curvature increases which eventually increases the focal length.
Regards
Curvature is defined as a lens inability to be flat, or the degree to which a lens curves. Now, lets think about this. A lens curvature represents a part of a circle. If you increase the curvature, in other words, curve the lense more, that would make the circle smaller. A radius is the distance from the center of the circle to the outside of the circle. So if you effectively make the circle smaller, you also decrease the radius of the circle. This is sort of tricky, what is known as an inverse or indirect relationship. If we increase the amount of curvature, we get a decrease in the amount of curvature radius. Or, we could go the other way, if we decrease the amount of curvature, we get an increase in the amount of curvature radius. In any event, when one factor moves, the other factor goes in an opposite direction. So, the bottom line is, increasing the curvature of the lens would decrease the radius of curvature.
We know that f=R/2
So on decreasing the curvature, the radius of curvature increases which eventually increases the focal length.
Regards
