JAMB - Physics (2019 - No. 57)
Which of the following statement about the electromagnet shown above is correct?
when the current flows from A to B, the end A will be in north pole
when the current flows from A to B, the end A will be south pole
when the current flows from A to B, the end B will be south pole
none of the above
解释
A - B = S - N.
Also, starting end of the current is south while terminating end is North.