The Spacing Between Adjacent Slits on a Diffraction Grating Is $\lambda$

Multiple Choice

The spacing between adjacent slits on a diffraction grating is 3 $\lambda$ . The deviation $\theta$ of the first order diffracted beam is given by:

A) sin( $\theta$ /2) = 1/3
B) sin( $\theta$ /3) = 2/3
C) sin( $\theta$ ) = 1/3
D) tan( $\theta$ /2) = 1/3
E) tan( $\theta$ ) = 2/3