[QUIZ/EM-09001] Electromagnetic Induction

A rod of mass $m$ and length $\ell$ and resistance $R$ rests and is free to slide on two parallel rails of zero resistance as shown in \Figref{em-fig-09008}. A uniform magnetic field fills the area surrounding the rails and is perpendicular and out of the plane of the paper. A battery of of voltage $V$ is connected as shown in the figure.

1. Qualitatively describe the motion of the rod when the  circuit is  completed by closing the key.
2. How the motion will change if the connection of the battery polarity is reversed magnetic field remains the same?
3. How the motion will change if the direction of the magnetic field is reversed and the battery is connected as shown?