Wavelength of X-rays falling at glancing angle of 30? on a crystal with atmic spacing 2 x 10-10 for the fist order diffraction is________________?

(A) 4 x 10-10 m (X)
(B) 2 x 10-10 m ()
(C) 0.02×10-10m (X)
(D) 20×10-10m (X)

Answers: Wavelength of X-rays falling at glancing angle of 30? on a crystal with atmic spacing 2 x 10-10 for the fist order diffraction is 2 x 10-10 m.