What is the Value of radius of curvature in newton ring?

The radius of curvature in Newton's rings is typically denoted as ( R ). It is the radius of the spherical surface of the lens used in the experiment. The value of ( R ) affects the spacing of the rings formed due to the interference of light, and it can be determined using the formula ( R = \frac{(D^2 n)}{4m\lambda} ), where ( D ) is the diameter of the m-th ring, ( n ) is the refractive index of the medium, ( m ) is the ring order, and ( \lambda ) is the wavelength of light used.