Light is incident normally on a diffraction grating through which the first order diffraction is seen at 32°. The second order diffraction will be seen at
Answer & explanation
Correct answer: option 4
For a grating $(e + d) \sin θ_n = nλ$
where (e + d) = grating element
$\sin θ_n = \frac{nλ}{(e + d)}$
for n = 1, $\sin θ_1 =\frac{λ}{(e + d)}=\sin 32°$
This is more than 0.5. Now sin θ2 will be more than 2 × 0.5, which is not possible.