## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

$B = 0.10~T$ (into the page)
We can find the magnetic field strength: $emf =B~L~v$ $B =\frac{emf}{v~L}$ $B =\frac{0.050~V}{(5.0~m/s)(0.10~m)}$ $B = 0.10~T$ If the magnetic field is directed into the page, then there would be a force on a positive charge directed toward the left. By Lenz's law, a potential difference is induced which opposes this. Therefore, the positive charges are on the left and the negative charges are on the right.