How can an electric field change the path of electrons inside an electron tube?

In an electron tube, an electric field changes the path of electrons by exerting a force on them, which is governed by Isaac Newton’s second law of motion. Because electrons carry a negative charge, they are accelerated toward positively charged electrodes (anodes) and slowed or repelled by negatively charged ones (cathodes).12

By applying specific voltages between electrodes, the electric field can be used to:
* Deflect the electron stream: This controlled deflection is fundamental to devices like the cathode-ray oscilloscope, where electric fields steer the beam to display information.3
* Modify speed and current: The field alters the velocity of electrons and regulates the number of electrons flowing through the tube.2
* Focus the beam: Electrode structures, such as an electron gun, use electric fields to constrict and collimate electrons into a precise beam.4

These movements are analyzed through electron ballistics, which studies how free electrons behave under the influence of these fields.5