Fig. 28-4 shows three long, parallel, current-carrying wires. the current directions are indicated for currents i1 and i3. the arrow labeled f represents the magnetic force acting on current i3. the 3 currents have equal magnitudes. what is the direction of the current i2?

Car batteries are often rated in amp-hours. this rating indicates the quantity of charge that can pass through the battery before the battery's chemical energy must be restored by the car's generator or some other source. the amp-hour unit is convenient for simple calculations. for example, a 60-amp-hour battery can supply a current of 1.0 a for 60 h (or 60 a for 1.0 h) before going dead. find the energy stored in the following. (a) a 58 a-h, 10 v car battery(b) a 1.3 a-h, 1.7 v flashlight battery