Question

For constructive interference to take place between two monochromatic light waves of wavelength λ, the path difference should be ______.

Options

• nλ

• `((2n - 1)λ)/4`

• `((2n + 1)λ)/2`

• `((2n - 1)λ)/2`

Answer 1

For constructive interference to take place between two monochromatic light waves of wavelength λ, the path difference should be nλ.

Explanation:

For constructive interference, the two monochromatic light waves should be in phase.

If the path difference is λ, then Φ the phase difference is 2π.

Thus for constructive interference, the two waves will be in phase in Φ is a multiple of 2π i.e 2nπ where n is an integer.

Thus, 2π correspond to nλ path difference.