The direction of Earth's magnetic field in the northern hemisphere is downward and to the north. If an east-west wire moves from north to south, in which direction does the current flow? I have no idea how to approach this problem. It was on my physics test and I got it wrong and I'm doing corrections for it right now. All I know is that Earth's geographic North is its magnetic South and vice-versa. The answer is east to west, but why?