Distance of 5th dark fringe from centre is $$4 \mathrm{~mm}$$. If $$D=2 \mathrm{~m}, \lambda=600 \mathrm{~nm}$$, then distance between slits is

A light of wavelength $$500 \mathrm{~nm}$$ is incident on a Young's double slit. The distance between slit and screen is $$D=1.8 \mathrm{~m}$$ and distance between slits is $$d=0.4 \mathrm{~mm}$$. If screen moves with a speed of $$4 \mathrm{~m} / \mathrm{s}$$, then with what speed first maxima will move?

Assertion : Distance between position of bright and dark fringe remain same in YDSE.

Reason : Fringe width, $$\beta=\frac{\lambda D}{d}$$

Assertion : Incoming light reflected by earth is partially polarised.

Reason : Atmospheric particle polarise the light.