Example 10.11 Application: Losses in Conducting Materials A circular disk of radius d ¼ 100 mm and thickness
c¼1mmis placed in a uniform,ACmagnetic field as in Figure 10.19a.The magnetic flux density varies asB¼B0sinωt [T]
and is directed perpendicular to the disk. The conductivity of the disk is σ ¼ 107 S/m, f ¼ 50 Hz, and the amplitude of the
magnetic flux density is 0.2 T:
(a) Calculate the instantaneous power dissipated in the disk due to induced (eddy) currents. Assume the magnetic field
is not modified by the induced currents and the field remains constant throughout the disk.
(b) What is the peak power loss at 100 Hz, under the same assumptions?