Question

Alternate bright and dark fringes are observed on a screen. What is the most probable cause of the problem?

• A. Light passing through a converging lens
• B. Light passing through a diverging lens
• C. Light passing through two very narrow slits
• D. Photos emitted from a metal
• E. Photos in an emission spectrum

Answer 1

The correct option is C Light passing through two very narrow slits

When light is passed through two very narrow slits, the waves emanating from the two slits meet each other. If the two are in same phase they undergo constructive interference (causing bright fringes) else if the two meet in opposite phases they undergo destructive interference (causing dark fringes).

Hence option C is the right answer.