X-rays of wavelength \(\lambda\) gets reflected from parallel planes of atoms in a crystal with spacing \(\mathrm{d}\) between two planes as shown in the figure. If the two reflected beams interfere constructively, then the condition for maxima will be, ( \(\mathrm{n}\) is the order of interference fringe)

• A

  \(\mathrm{d} \tan \theta=\mathrm{n} \lambda\)
• B

  \(\mathrm{d} \sin \theta=n \lambda\)
• C

  \(2 \mathrm{~d} \cos \theta=\mathrm{n} \lambda\)
• Correct answer
  D

  \(2 \mathrm{~d} \sin \theta=\mathrm{n} \lambda\)

Hence, the correct answer is option: 'D'.