Answer
Equation of lens law
[tex]\dfrac{1}{f}=(n -1 )(\dfrac{1}{R_1}-\dfrac{1}{R_2})[/tex]
where f is the focal length of the lens
n is the refractive index of the lens
R_1 and R_2 is the radius of curvature of the lens.
From the above expression we can see that focal length of the lens is directly proportional to radius of curvature.
hence, when the radius of curvature of the lens increases the focal length of the lens will also increase.
