Question

How might a loop of wire carrying a current be used as a compass? Could such a compass distinguish between north and south? Why or why not?

Short answer

We would have to know the direction of the current in the loop in order to determine where is north and where is south.

Step-by-step solution

Direction of current

The loop of wire will have its magnetic moment perpendicular to its plane and will tend to move so that magnetic field are in the direction of this moment. We could with this simple device determine the N-S direction only but in order to know where is north and where is south, we would have to know the direction of the current in the loop in order to determine the direction of its magnetic moment.

Conclusion

Hence, we would have to know the direction of the current in the loop in order to determine the direction of its magnetic moment.