Physics 9702/52 — May/June 2018

A student is investigating the reflection of light from a compact disc (CD), as shown in Fig. 1.1.

The student observes on the screen a pattern of maxima and minima which is similar to that produced by a diffraction grating. The distance $h$ is measured to one of the maxima.

It is suggested that the relationship between $h$ and the wavelength $\lambda$ of the incident light is

where $n$ is the order of the maximum and $d$ and $B$ are constants.

Design a laboratory experiment to test the relationship between $h$ and $\lambda$.
Explain how your results could be used to determine values for $d$ and $B$.

You should draw a diagram, on page 3, showing the arrangement of your equipment. In your account you should pay particular attention to

• the procedure to be followed,
• the measurements to be taken,
• the control of variables,
• the analysis of the data,
• any safety precautions to be taken.