Fig. 1.1 shows a bar magnet attached to a spring. -spring N bar magnet S Fig. 1.1 The bar magnet is displaced a distance x from its equilibrium position and released. It then oscillates vertically. A student investigates how the maximum induced electromotive force (e.m.f.) E in a coil placed below the magnet depends on x. It is suggested that the relationship between E and x is E = αBNx√(k/m) where B is the magnetic flux density at one of the poles of the bar magnet, N is the number of turns on the coil, k is the spring constant, m is the mass of the magnet and α is a constant. Design a laboratory experiment to test the relationship between E and x. Explain how your results could be used to determine a value for α. 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.