In our discussion of the solenoid in Figure 20.33B, we claimed that the field outside th...

In our discussion of the solenoid in Figure 20.33B, we claimed that the field outside the solenoid is much smaller than the field inside and that it is a good approximation to assume the field outside a very long solenoid is zero. Explain how this approximation can be consistent with the property that magnetic field lines always form closed loops.

(reference figure 20.33B)