Monochromatic light is passed through two slits in one screen and the resulting interference pattern is projected onto a second screen a large distance (compared to the slit spaccing) from the first. What will happen to the distance between bright spots on the second screen if the distance between the two slits in the first screen is made smaller?

The bright spots will get closer together.

Explanation:

Coloured fringes are formed at the screen if monochromatic light is replaced by the white light.

The distance between bright spots on the second screen will decrease if the distance between the two slits in the first screen is made smaller

The rules of geometrical optics hold when the widths of the slits are significantly greater than the wavelength of the light, —the light casts two shadows, and there are two illuminated regions on the screen. However, as the slits decrease in width, the light diffracts into the geometrical shadow, and the light waves overlap on the screen. 

The bright spots will therefore get closer together.