In a thin film interference, which of the following conditions leads to a dark fringe?

1 question

1 item

Q: In a thin film interference, which of the following conditions leads to a dark fringe?

Solution: A dark fringe occurs when the path difference is an odd multiple of the wavelength (λ/2), leading to destructive interference.

Steps: 5

Step 1: Understand that thin film interference happens when light waves reflect off the top and bottom surfaces of a thin film.
Step 2: Know that when light waves meet, they can either add together (constructive interference) or cancel each other out (destructive interference).
Step 3: Recognize that a dark fringe appears when the light waves cancel each other out.
Step 4: Learn that this cancellation happens when the path difference between the two waves is an odd multiple of half the wavelength (λ/2).
Step 5: Conclude that for a dark fringe, the condition is that the path difference = (2n + 1)(λ/2), where n is an integer (0, 1, 2, ...).