In a thin film interference, if the film is of thickness t and the refractive in
Practice Questions
Q1
In a thin film interference, if the film is of thickness t and the refractive index is n, what is the condition for constructive interference?
2nt = (m + 1/2)λ
2nt = mλ
2nt = (m - 1/2)λ
2nt = mλ/2
Questions & Step-by-Step Solutions
In a thin film interference, if the film is of thickness t and the refractive index is n, what is the condition for constructive interference?
Step 1: Understand that thin film interference occurs when light waves reflect off the top and bottom surfaces of a thin film.
Step 2: Recognize that for constructive interference, the waves must be in phase, meaning they reinforce each other.
Step 3: Know that the path difference between the two waves is important. The path difference is given by 2nt, where n is the refractive index and t is the thickness of the film.
Step 4: For constructive interference, this path difference must equal an integer multiple of the wavelength (λ) of the light used. This is expressed as 2nt = mλ, where m is an integer (0, 1, 2, ...).
Step 5: Conclude that the condition for constructive interference in a thin film is 2nt = mλ.
