Michael Faraday unsuccessfully attempted to measure the potential difference across the River Thames due to the flow of water $($which is a good conductor due to dissolved salts$)$ in the earth's field. At Waterloo Bridge, where Faraday made his attempt, the river is $200$ m wide and flows eastward at $2\mathrm{.}0$ m$/$s$.$ The earth's magnetic field here has a magnitude of $50$ T and is tipped $65$ from the horizontal, so it has both horizontal $($north$)$ and vertical $($down$)$ components.

Part A

Is the north or south riverbank at a higher potential? $$

The south riverbank is at a higher potential.The riverbanks are at the same potential.The north riverbank is at a higher potential.