A Diffraction Grating Is to Be Used to Find the Wavelength

Short Answer

A diffraction grating is to be used to find the wavelength of the light in the emission spectrum of a gas.The grating spacing is not known,but a light having a known wavelength of 632.8 nm is deflected by 43.2° away from the central maximum in the second order by this grating.Light of the wavelength to be measured is deflected by 48.2° away from the central maximum in the second order.What is the wavelength of this light?