Question

X-rays of wavelength λ get reflected from parallel planes of atoms in a crystal with spacing d between two planes as shown in the figure. If the two reflected beams interfare constructively,Then the condition for maxima will be(n is the order of interference fringe)

• A. d tanθ=nλ
• B. d sinθ=nλ
• C. 2d cosθ=nλ
• D. 2d sinθ=nλ

Answer 1

Answer: (D)

2d sinθ=nλ

Answer 2

In the diagram provided, the path difference between the beams reflected from consecutive planes is AM +AN =2 d sin θ. For constructive interference to occur, the path difference must equal an integer multiple of the wavelength, represented as 2 d sin θ =nλ.

The correct option is(D): 2d sinθ=nλ