Physics 9702 · AS & A Level · The diffraction grating
The diffraction grating — practice question
A diffraction grating diffracts monochromatic light. Using this as a guide, explain what is meant by
(a(i))[2]
diffraction.
(a(ii))[1]
coherence.
(a(iii))[1]
superposition.
(b)[3]
A parallel beam of red light of wavelength $630\,\text{nm}$ is incident normally on a diffraction grating of $450\,\text{lines mm}^{-1}$. Calculate the number of diffraction orders produced.
(c)[3]
The red light used in (b) is swapped for blue light. State and explain how the diffraction pattern changes.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Diffraction is the bending or spreading of light at an edge or slit” …