A student moves a metal bar upwards between the poles of a magnet, as shown in Fig. 6.1. [Figure 6.1] The ammeter connected to the metal bar shows a small positive reading as the bar moves.

1. (a)Explain why there is a reading on the ammeter.[2]
2. (b)Complete Table 6.1 by stating what the ammeter shows when the metal bar moves in the direction shown by the arrow in each diagram. [Table 6.1][3]
3. (c)The student finds that using a stronger magnet increases the reading on the ammeter. State one other way in which the student can produce a larger reading on the ammeter, using the same rod.[1]
4. (d)Describe how Lenz's law applies when the bar is moved upwards.[1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.