Imagine that we have two metal rails 20 cm apart connected by a light bulb. The rails are placed in a 1.0 T magnetic field oriented vertically downward. We then constrain a bar to slide on the rails toward the lightbulb in this magnetic field. How fast do we have to move the bar to put a voltage difference of 3.0 V across the bulb? In what direction does the current flow?
We have the electromotive force E (V) induced in a wire of length L traveling at velocity v (m/s) in a magnetic field of strength B (T) is:
The solution gives all steps along with proper explanations so that you can solve similar problems yourself.