Problem 7.17 A long solenoid of radius a, carrying n turns per unit length, is looped by a wire with resistance R, as shown in Fig. 7.28. W R FIGURE 7.28 15 This is not at all the way electric fields actually behave in coaxial cables, for reasons suggested in the previous footnote. See Sect. 9.5.3, or J. G. Cherveniak, Am. J. Phys., 54, 946 (1986), for a more realistic treatment. 7.2 Electromagnetic Induction 321 (a) If the current in the solenoid is increasing at a constant rate (dI/dt = k), what current flows in the loop, and which way (left or right) does it pass through the resistor? (b) If the current I in the solenoid is constant but the solenoid is pulled out of the loop (toward the left, to a place far from the loop), what total charge passes through the resistor?

The figure below is a cross-sectional view of a coaxial cable. The center conductor is surrounded by a rubber layer, an outer conductor, and another rubber layer. In a particular application, the current in the inner conductor is I, = 1.16 A out of the page and the current in the outer conductor is I, = 2.90 A into the page. Assuming the distance d = 1.00 mm, answer the following. d d (a) Determine the magnitude and direction of the magnetic field at point a. magnitude HT direction -Select--- (b) Determine the magnitude and direction of the magnetic field at point b. magnitude UT direction ---Select---