What affect will a change in the distribution of charge have on the sample. For example, will it induce a potential difference? Discuss this with your partners and record your thoughts in your journal.
Notice how there are more electrons (balls) on the far side of the board. This distribution of the charge creates a potential difference. If electrons flow uphill, why don't they roll up to the near side of the board?
Answer: There is a balance between the magnetic force which pushes the electrons to the far side of the board, and the tendency of the electrons to roll uphill. The Hall EMF (due to the magnetic force)and the potential difference (due to the separation of charge), balance.
Go to Exercise 3.