Question

what would happen if we place two prisms side by side such that the adjacent sides are parallel and pass a ray of white light through them​

Answer 1

Answer:

Two prisms placed next to each other such that their adjacent sides are parallel ,behave like a glass slab because a ray of white light falling on the first prism will disperse the light into its seven constituent colours. ... This causes the spectrum or the band of seven colours to reunite and form the ray of white light.

Explanation:

Answer 2

Answer:

Two prisms placed next to each other having adjacent faces parallel act as GLASS SLAB because when a ray of white light falls on the first prism it will disperse the light into its seven constituent colours which then falls on the parallel adjacent side of the second prism which does not disperse the light but gives it.