|
One of Kaleb's favorite pastimes is to play with his Sesame Street magnets on the refrigerator. He knows that he can pull them off (with a little effort on his part) and then he can place them back on the refrigerator wherever he wants to do so. What Kaleb doesn't know is that each of these magnets has two poles, a North pole and a South pole. The magnets have the opposite pull of the refrigerator. If they did not, they would repel each other and the magnets would fall to the floor. The magnetic fields of the magnet are wide enough that the magnet is actually able to hold paper to the refrigerator.
 When a car comes near the street light, it rolls over some coils of wire that are buried deep beneath the street. When this happens, electromagnetic induction occurs and the change in the magnetic fields of the coils causes an increase in the voltage, causing the stop light to change. This is consistent with Faraday's Law, which says that a time varying magnetic field induces an electric field.
|
