Answer:
Interference pattern
Step-by-step explanation:
When a monochromatic light is incident on a thin barrier having two slits, an interference pattern can be seen on the screen placed in front of the slits. The alternate dark and bright fringes appear on the screen.
This can be explained on the basis of wave nature of light. When the monochromatic light passes through the slits, the waves interfere and produce pattern on the screen.