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.

An unpolarised beam of intensity $$2 a^2$$ passes through a thin polaroid. Assuming zero absorption in the polaroid, the intensity of emergent plane polarised light is