Question:
A wire loop smears in a horizontal plane. Alongside the loop is a vertical bar magnet south end up. The bar magnet is divide by the plane of the loop. A person is shifting the bar magnet rapidly away from the loop. What is the path of the current if any induced to flow in the loop?
Answer:
Refer to the diagram below:
1. The magnetic field lines expand out of the north end of a magnet and into the south end. (Nature of a bar magnet.)
2. With the north end of the magnet down as well as the loop beside the magnet as shown such magnetic field lines pass upward through the loop.
3. Magnetic field lines are more intimately packed close to the magnet than they are far from the magnet.
4. The motion of the magnet affects the loop to be farther and farther from the magnet as time goes by.
5. On the basis of 2, 3 and 4 above and the fact that a person is moving the bar magnet away from the loop the person is moving the magnet to the right in the diagram above while the loop stays put, the numerous upward magnetic field lines through the loop is decreasing with time.
6. By Faraday's Law the changing numerous magnetic field lines induces a current in the loop.
7. By Ampere's Law the encouraged current produces a magnetic field.
8. By Lenz's Law the magnetic field created by the induced current is upward to make up for the diminishing number of upward directed magnetic field lines from the magnet through the loop.
9. By the right-hand rule for something straight, something curly the induced current has to be counter clockwise in the loop as viewed from above in order to produce an upward-directed magnetic field.
