Question

In a young's double slit experiment the spacing between the slits is 0.3 mm and the screen is kept at distance of 1.5 m. the second bright fringe is found 6mm from the central fringe.the wavelength of light is used in experiment is

Answer 1

Distance between the slits d = 0.3mm = 0.3 x 10^-3 m. Distance between the slits and the screen D= 1.5m.

Distance between the central fringe and second (n=2) fringe.

U= 6mm = 6 x 10^-3 m. in case of consecutive interference, we have the relation for the distance between two fringes is u = (nx wavelength x D)/d; wavelength =(uxd)(uxD). The wavelength of light is 600 nm.

Answer 2

$\huge \sf 600 \: \: nm$