Chapter 29, Problem 29.68P

DATA You measure the magnitude of the external force $\stackrel{\to }{F}$ that must be applied to a rectangular conducting loop to pull it at constant speed v out of a region of uniform magnetic field $\stackrel{\to }{B}$that is directed out of the plane of Fig. P29.68. The loop has dimensions 14.0 cm by 8.00 cm and resistance 4.00 × 10−³ Ω it does not change shape as it moves. The measurements you collect are listed in the table.

(a) Plot the data as a graph of F versus ʋ. Explain why the data points plotted this way lie close to a straight line, and determine the slope of the best-fit straight line for the data. (b) Use your graph from part (a) to calculate the magnitude B of the uniform magnetic field. (c) In Fig. P29.68, is the current induced in the loop clockwise or counterclockwise? (d) At what rate is electrical energy being dissipated in the loop when the speed of the loop is 5.00 cm/s?

Figure P29.68