To practice problem-solving strategy 30.1: inductors in circuits. a circuit has a 1 v battery connected in series with a switch. when the switch is closed, the battery powers two paths in parallel, one of which has a resistor of resistance r1 = 95 ω in series with an inductor of inductance l = 1.5×10−2 h , while the other has a resistor of resistance r2 = 360 ω . what is the current supplied by the battery at a time t = 0.4 ms after the switch is closed?

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.)