The possible plane separation related to Bragg reflection

[songoku]

Homework Statement

An X ray beam with wavelength 0.16 nm is incident on a set of planes of certain crystal. The first Bragg reflection is observed for an incidence angle of 30 degree. The reflection satisfies the relation 2d sin q = nl. The possible planes separation d for the reflection is
a. 0.136 nm and 0.272 nm
b. 0.136 nm and 1.36 nm
c. 0.136 nm and 13.6 nm
d. 0.136 nm

Relevant Equations

2d sin q = nl (given by question)

2d sin q = nl

d = nl / (2 sin q)

d = (1 x 0.16) / (2 sin 30^o) = 0.16 nm

But 0.16 is not in the option. And how to find other value of d?

Thanks

 

[Charles Link]

Looks to me like a typo, that should have $\lambda=.136$ nm. Perhaps someone else has a better explanation.

 

[songoku]

Thank you very much for the help Charles Link