The diffraction grating — Physics 9702 AS & A Level Question & Worked Solution

(a(i))[1]

For a progressive wave, state what the term wavelength means.

(a(ii))[1]

For a progressive wave, state what the term amplitude means.

(b(i)-1)[1]

Diffraction happens for the light waves at every slit in the grating. The waves leaving the slits are coherent. Explain what is meant by diffraction.

(b(i)-2)[1]

Diffraction takes place for the light waves at each slit of the grating. The waves coming from the slits are coherent. Explain what is meant by coherent.

(b(ii))

Laser light has wavelength \(650\,\text{nm}\). In Fig. 4.1, the angle between the third-order diffraction maxima is \(68^\circ\).

(b(i).1)[1]

Explain the meaning of diffraction.

(b(i).2)[1]

Explain the meaning of coherent.

(b(iii))[2]

Red laser light is replaced by blue laser light. State and explain what change, if any, occurs to the angle between the third-order diffraction maxima.

The diffraction grating — practice question

Worked solution & mark scheme