Research Papers in Physics and Astronomy


Date of this Version



Published in Physics, by Henry Semat and Robert Katz, New York: Rinehart & Company, Inc., 1958. Copyright © 1958 Henry Semat and Robert Katz. All rights reserved. Used by permission.


Ampere was the first to show that wires carrying current experienced forces when placed in magnetic fields. Later it was shown that charged particles moving in magnetic fields also experience forces. Common applications of these phenomena are the electric motor, the galvanometer, and the cathoderay tube. Since a moving electric charge is equivalent to a current, we shall first consider the force acting on a charge q moving with velocity v in a magnetic field of induction B. Experiment shows that the force F acting on the charge q is at right angles to the directions of both v and B. This provides us with a basic distinction between the two magnetic field vectors Band H.

Included in

Physics Commons