# Magnetic Fields Due to Currents

## A Current Carrying Coil as a Magnetic Dipole

A Current-Carrying Coil as a Magnetic Dipole So far we have examined the magnetic fields produced by current in a long straight wire, a solenoid, and a toroid, We turn our attention here to the field produced by a coil carrying a -current. You saw in Section 29-9 that such a coil behaves as a  magnetic dipole in …

## Solenoids and Toroids

Solenoids and Toroids Magnetic Field of a Solenoid We now turn our attention to another situation in which Ampere’s law proves useful. It concerns the magnetic field produced by the current in a long, tightly wound helical coil of wire. Such a coil is called a solenoid . We assume that the length of the solenoid is much …

## Ampere’s Law

Ampere’s Law We can find the net electric field due to any distribution of charges with the inverse square law for the differential field if (Eq. 30-2), but if the distribution is complicated,  we may have to use a computer. Recall, however. that if the istribution has   lanar. cylindrical. or spherical symmetry, we can apply Gauss’ …

## Force Between Two Parallel Currents

Force Between Two Parallel Currents Two long parallel wires carrying currents exert forces on each other. Figure 30-9 shows two such wires, separated by a distance d and carrying currents io and ib Let us analyze the forces on these wires due to each other. We seek first the force on wire b in  due to the current …

## Calculating the Magnetic Field Due to a Current

Calculating the Magnetic Field Due0 to a Current As we discussed in Section 29-1, one way to produce a magnetic field is with moving charges-that is, with a current. Our goal in this chapter is to calculate the magnetic field that is produced by a given distribution of currents. We shall use the same basic procedure we used …

## Magnetic Fields Due to Currents

Magnetic Fields Due to Currents This is the way we presently launch materials into space. However, when we begin mining the Moon and the asteroids, where we will not have a source of fuel for such conventional rockets, we shall need a more effective way.  electromagnetic lunchers may be the answer. A small prototype, the electromagnetic rail gun, can presently accelerate …