Modern Physics
Set 1
Animation 2

Description

This physlet shows an electron fired into a magnetic field (B). The magnetic field provides a force on the electron perpendicular to the electron's motion. As viewed in the applet the electron moves in a circular path towards the bottom of the screen.

In 1897 J.J. Thomson used a high voltage in a cathode ray tube to project electrons between both a magnetic and electric field. He designed the apparatus so that one field would deflect the electron up and the other field would deflect the electron down. He reasoned that the force from the electric field would equal the force from the magnetic field when the beam was neither defected up nor down.

There is a magnetic field (B) between the plates represented by the color pink. The field B, is directed perpendicular to the screen. To add an electric field enter a non-zero value into the Electric Field box and click "Fire Charge". Launch speed m/s Electric field N/C