(a) The current I in a metal wire is given by the expression I = Anve. State what is meant by the symbols A and n. (b) The diameter of a wire XY varies linearly with distance along the wire as shown in Fig. 7.1. [Figure 7.1] There is a current I in the wire. At end X of the wire, the diameter is d and the average drift speed of the free electrons is v_x. At end Y of the wire, the diameter is d/2. On Fig. 7.2, sketch a graph to show the variation of the average drift speed with position along the wire between X and Y. [Figure 7.2]

1. (a)State what is meant by the symbols A and n. A: n:[2]
2. (b)On Fig. 7.2, sketch a graph to show the variation of the average drift speed with position along the wire between X and Y.[2]

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