A student is investigating the reflection of light from a compact disc (CD), as shown in Fig. 1.1. [Figure 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 λ of the incident light is h = nλ/d + B 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 λ. 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.