Question

Using monochromatic light of 410 nm wavelength, a single thin slit forms a diffraction pattern, with the first minimum at an angle of 40.0° from central maximum. The same slit, when illuminated by a new monochromatic light source, produces a diffraction pattern with the second minimum at a 60.0° angle from the central maximum. What is the wavelength of this new light?a. 256 nm b. 283 nm c. 307 nm d. 329 nm e. none of these

Answer 1

Answer:

c. 307 nm

Explanation:

angular position of first dark fringe =  λ / d ,   λ is wavelength and  d is width of slit .

(40 x π ) / 180 = 410 / d

angular position of second  dark fringe =  2 x λ / d ,   λ is wavelength and  d is width of slit .

(60 x π ) / 180 = 2 x λ / d

Dividing these equations

60 / 40 =  2 x λ / 410

λ = 307.5 nm.