Welcome to Physics Problems Q&A, where you can ask questions and receive answers from other members of the community.

Direction of magnetic field near permanent magnets

1 vote

Consider the following question and my answer

I believe my answer for 1 is right. What about for 2? Are the arrows always vertical/horizontal?

And what about 3?

asked Mar 23, 2017 in Physics Problems by member192 (280 points)

1 Answer

1 vote
Best answer

The magnetic field at any point near multiple magnets is the vector sum of the field from each individual magnet. The same Superposition Principle applies to the electric field around a system of charges.

Look at the field from an individual magnet and try to add the fields :

Your answers to 1 and 2 look ok, but you have some small mistakes in 3, especially in the region between the two magnets.

In the diagram below, the red and green arrows show the individual fields, the blue arrows show the resultant. Note that the strength of the magnetic field decreases rapidly as you move away from the magnet, so if one magnet is significantly closer to the compass the other will have little effect on the resultant magnetic field at that point.

The points equidistant from the NN and NS poles are where both magnets have equal effect.

answered Mar 23, 2017 by sammy gerbil (28,896 points)
edited Mar 24, 2017 by sammy gerbil