A beam of monochromatic light is incident on a diffraction grating of N lines per unit length. The angle between the first orders is θ₁.

What is the wavelength of the light?

A.     \(\frac{{\sin {\theta _1}}}{N}\)

B.     N sin θ₁

C.     N sin\(\left( {\frac{{{\theta _1}}}{2}} \right)\)

D.     \(\frac{{\sin \left( {\frac{{{\theta _1}}}{2}} \right)}}{N}\)

D