- #1
Aziza
- 190
- 1
In our lab we determined the charge to mass ratio e/m of electron by creating electron beam and making it spin in a circle using a magnetic field from helmholtz coils. According to the pasco lab manual for this experiment, the velocity of the electrons in the beam will be lower than theoretical (because of nonuniform acceleration and collisions with helium atoms which made the circle glow), and thus the lab manual says that our measured e/m will be HIGHER than theoretical...
But I thought our measured should be LOWER than theoretical? Since (e/m)=(v^2)/(2ΔV) where v is velocity and ΔV is accelerating voltage, then lower v for the same ΔV should yield lower e/m...
But I thought our measured should be LOWER than theoretical? Since (e/m)=(v^2)/(2ΔV) where v is velocity and ΔV is accelerating voltage, then lower v for the same ΔV should yield lower e/m...