The magnetic field at one place on the earth's surface is 55 uT in strength and tilted 60 degrees down from horizontal. A 150-turn coil having a diameter of 3.8cm and a resistance of 2.00 Ohms is connected to a 1.20 uF capacitor rather than to a current meter. The coil is held in a horizontal plane and the capacitor is discharged. Then the coil is quickly rotated 180 degrees so that the side that had been facing up is now facing down. Afterward, what is the voltage across the capacitor?

Certain bacteria (such as aquaspirillum magnetotacticum) tend to swim toward the earth’s geographic north pole because they contain tiny particles, called magnetosomes, that are sensitive to a magnetic field. if a transmission line carrying 100 a is laid underwater, at what range of distances would the magnetic field from this line be great enough to interfere with the migration of these bacteria? (assume that a field less than 5% of the earth’s field would have little effect on the bacteria. take the earth’s field to be 5.0 * 10-5 t, and ignore the effects of the seawater.)