The intensity pattern for single slit diffraction is shown in the diagram (The vertical units are arbitrary) The wavelength of the light used is $\lambda$

b On a copy of the axis draw a graph to show how the intensity varies with diffraction angle for a slit with 

(i) Width $\frac{b}{2}$ and wavelength $\lambda /2$

Light is incident normally on two narrow parallel slits a distance of $1.00\mathrm{mm}$ apart. A screen is placed a distance of $1.2\mathrm{m}$ from the slits. The distance on the screen between the central maximum and the centre of the $n=4$ bright spot is measured to be $3.1\mathrm{mm}$.

a. Determine the wavelength of light.

Light is incident normally on two narrow parallel slits a distance of $1.00\mathrm{mm}$ apart. A screen is placed a distance of $1.2\mathrm{m}$ from the slits. The distance on the screen between the central maximum and the centre of the $n=4$ bright spot is measured to be $3.1\mathrm{mm}$.

b. This experiment is repeated in water (of refractive index $1.33$). Suggest how the distance of $3.1\mathrm{mm}$ would change, if at all.

The graph shows the intensity pattern from a two-slits interference experiment.

a. Determine the separation of the slits in terms of the wavelength of light used.

The graph shows the intensity pattern from a two-slits interference experiment.

b. Suggest how the pattern in the previous question change if the slit separation changes.

A grating with $400 \mathrm{lines} \mathrm{per} \mathrm{mm}$ is illuminating with the light of wavelength $600.0\mathrm{nm}$.

a. Determine the angles at which maxima are observed.