Answer:
The distance between the bright fringes is 2.19 mm
Explanation:
Distance of the screen from the slits, d = 1.9 m
Slit width, w = 0.11 mm = [tex]0.11\times 10^{- 3}\ m[/tex]
Wavelength, [tex]\lambda = 695\ nm[/tex]
Wavelength, [tex]\lambda' = 407\ nm[/tex]
To calculate the distance between the second order bright fringe:
[tex]y_{n} = \frac{n\lambda d}{w}[/tex]
[tex]y'_{3} = \frac{n\lambda' d}{w} = \frac{3\times 695\times 10^{- 9}\times 1.9}{0.11\times 10^{- 3}} = 0.036\ m[/tex]
[tex]y_{2} = \frac{2\times 407\times 10^{- 9}\times 1.9}{0.11\times 10^{- 3}} = 0.014\ m[/tex]
Distance, |x| = [tex]y'_{3} - y_{2}[/tex]
|x| = [tex]0.036 - 0.0141 = 0.0219 m = 2.19\ mm[/tex]
