Question

in newton's ring experiment, the diameter of 10th dark ring is 0.433 cm. find the wavelength of incident light, if the radius of curvature of the lens is 70cm​

Answer 1

Answer:

Given that-

Diameter of 10th dark ring = 0.433 cm

and Radius of curvature of lens is = 70 cm

Wavelength of light (λ) = ?

We know that for Dark ring –

$D^{2} _{n} = 4n$λR

Put the given values in this formula

λ = $\frac{D^{2} _{10} }{4nR}$

λ = $\frac{(0.433)^{2} }{4×10×70}$

λ = 6.696 × $10^{-5}$ cm

λ = 6.696 × $10^{-7}$ m

Ans