This comes from one of the free response questions from the AP Physics B 2014 exam.
5. (15 points) A conducting rod of mass $m$ and length $L$ hangs at rest from two identical conducting springs, each with spring constant $k$, as shown in the figure at left above. The upper ends of the springs are fixed at points $P$ and $Q$, and the rod is in a uniform magnetic field $\mathbf{B}$ directed into the page. A battery is then connected between points $P$ and $Q$, as shown in the figure at right above, resulting in a current $I$ in the rod. The rod is displaced downward, eventually reaching a new equilibrium position with the springs stretched an additional distance $\Delta y$.
(a) Which point, $P$ or $Q$, is connected to the positive terminal of the battery? Justify your answer.
The answer is Q. But I put P. I said there will be a change and increase in flux. This means, by Lenz's Law, that there will be an induced magnetic field in the opposite direction. Using the hand rule, you point your thumb in the direction of the magnetic field, and CURL your fingers towards the direction of current, which makes it counter-clockwise. Thus, it can be seen that P is the right answer.
Why is my answer wrong? My other classmates are telling me the answer is Q, why?