Question

X-rays are incident normally on a crystal of lattice constant 0.6 nm. The first order reflection of diffraction from the crystal occurs at an angle of ${30}^{\circ }$. What is the wavelength of X-rays used?

• A. 3.0 nm
• B. 0.6 nm
• C. 1.2 nm
• D. 2.4 nm

Answer 1

The correct option is B

0.6 nm

From the Bragg's equation, $2dsin\theta =n\lambda \Rightarrow 2\times 0.6\times sin{30}^{\circ }=1\times \lambda \therefore \lambda =0.6nm$
Hence, the corrcet choice is (b).