Question $5$: In Young's double$-$slit experiment, the double$-$slit is illuminated by a monochromatic light. The entire set

up is immersed in water. Identify and justify whether these acts can$/$cannot restore the original fringes $($when not

immersed in water$).$

Bringing the slits close together.

Moving the screen away from the double$-$slit.

Increasing the wavelength of light.

Introduce thin transparent slab in front of the double$-$slit.