A metal wire of mass m = 24.1 mg can slide with negligible friction on two horizontal parallel rails separated by distance d = 2.56 cm. The track lies in a vertical uniform magnetic field of magnitude 56.3 mT. At time t = 0, device G is connected to the rails, producing a constant current i = 9.13 mA in the wire and rails (even as the wire moves). At t = 61.1 ms, what are the wire’s (a) speed and (b) direction of motion (left or right)?

In the figure, an electron with an initial kinetic energy of 3.80 keV enters region 1 at time t = 0. That region contains a uniform magnetic field directed into the page, with magnitude 0.0100 T. The electron goes through a half-circle and then exits region 1, headed toward region 2 across a gap of 30.0 cm. There is an electric potential difference AV = 2000 V across the gap, with a polarity such that the electron's speed increases uniformly as it traverses the gap. Region 2 contains a uniform magnetic field directed out of the page, with magnitude 0.0168 T. The electron goes through a half-circle and then leaves region 2. At what time t does it leave? Number i Units × B₁ Region 1 Region 2 OB₂

A rod of length L = 10.0 cm that is forced to move at constant speed v = 5.00 m/s along horizontal rails. The rod, rails, and connecting strip at the right form a conducting loop. The rod has resistance 0.400 Ω; the rest of the loop has negligible resistance. A current i = 100 A through the long straight wire at distance a = 10.0 mm from the loop sets up a (nonuniform) magnetic field through the loop. Find the (a) emf and (b) current induced in the loop. (c) At what rate is thermal energy generated in the rod? (d) What is the magnitude of the force that must be applied to the rod to make it move at constant speed? (e) At what rate does this force do work on the rod?

A straight conductor of length L moves with an acceleration A =0.1 ms-2 at right angles to a magnetic field of uniform strength B=10.2 T. Calculate L, considering that the e.m.f., ? = BLv, between the ends of the conductor increased from 0 to 5 V during the first 20 s after the beginning of motion.