Experiment: Electron charge to Mass Ratio
In the e/m experiment, a Uniform magnetic field is generated by Helmholtz coils with a radius of 0.158 m and N = 130 turns.
The coils are parallel to the plane of the figure.
The electron gun is located at the bottom.
The electron trajectory is shown with a green line.
The current in the Helmholtz coils is I and can be varied with the slider.
The accelerating voltage of the electron gun is V and can also be varied with the slider.
Instructions:
a) Determine the physical variable that will remain constant and select its value.
b) Select the value of the other physical variable according to your table and measure the radius of the trajectory using the grid on the graph.
Theoretical value for e/m is 1.759 × 10¹¹ C/kg
Note: The scale of the graph is in meters.