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

Question:

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.

В + в, I1 -х I2