Question

in Young's double slit experiment the distance of screen from the double slit is 1m anf slits are separated by distance 1mm.if the position of 3rd dark fringe from the centre of screen is 1.5mm.find the wavelength of light used​

Answer 1

...... Hope this helps you

Answer 2

here D=1m

d=1mm

distance of nth dark fringe is given by ( 2n-1)D(lamda)/2d

given third dark fringe is at distance 1.5mm

using formula

1.5×10^-3=5×1×lamda/2×1×10^-3

SOLVING we get

lambda(wavelength of light used)=6×10^-7m