Light is incident normally on a diffraction grating through which the first difffration is sceen at `32^@` in the second order diffraction will be

Options

A. `84^(@)`
B. `48^(@)`
C. `64^(@)`
D. none of these

Answer

D

Explanation

For second-order diffraction,
  `sintheta_(2)-(2lambda)/(d)=2sintheta_(1) = 2 sin 32^(@) > 1`, which is not possible.
Hence, there is no second-order diffraction