CAPE Physics Unit 1 · 2007 (Specimen) · Paper 1 · Question Q20

Light from a source is incident normally on a diffraction grating which has 2000\text{ lines per mm}. What is the wavelength of the light if the first order maximum makes an angle of 30^\circ with the zero order?

1. (A)250\text{ nm}
2. (B)433\text{ nm}
3. (C)125\text{ nm}
4. (D)866\text{ nm}