Solution: There are two methods to solve this problem: (1) The increase in the magnetic flux density causes an induced
electric field intensity in the closed loop, which may be calculated using Eq. (10.5). This electric field generates a current
density in the material of the loop equal to σE. Assuming the current density is uniform in the conductor, the current is found
by multiplying the current density by the cross-sectional area of the conducting ring. (2) The increase in the magnetic flux
density induces an emf in the ring. This emf produces a current equal to the emf divided by the resistance of the loop. We
show both methods.
Method (1) The change in flux density produces an electric field intensity E in the direction shown in Figure 10.20b,
assuming that the flux density increases as indicated. The induced electric field intensity, induced current density, and
induced current can now be calculated using Eq. (10.5):