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________________?

Wavelength of X-rays falling at glancing angle of 30? on a crystal wit

1.	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
B.	2 x 10-10 m
C.	0.02×10-10m
D.	20×10-10m
Answer» C. 0.02×10-10m