Walker, Halliday & Resnick — Induction and Inductance: Problem 1

1 In Fig. 30-21, a metal rod is forced to move with constant velocity $\vec{v}$ along two parallel metal rails, connected with a strip of metal at one end. A magnetic field of magnitude $B = 0.125 \text{ T}$ points out of the page. (a) If the rails are separated by $L = 25.0 \text{ cm}$ and the speed of the rod is $38.0 \text{ cm/s}$, what emf is generated? (b) If the rod has a resistance of $18.0 \text{ \Omega}$ and the rails and connector have negligible resistance, what is the current in the rod? (c) At what rate is energy being transferred to thermal energy? (d) What is the magnitude of the leftward force that causes the rod to move?