A student is investigating the resistance of a light-dependent resistor (LDR) separated from a source of light by different depths of water as shown in Fig. 1.1. light LDR water [Figure 1.1] It is suggested that the relationship between the resistance R of the LDR and the depth d of the LDR in the water is R = 4πd² K where K is a constant. Design a laboratory experiment to test the relationship between R and d. Explain how your results could be used to determine a value for K. 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.