Observation of the Movement of Electrons in Electric and Magnetic Fields, the Determination of the Specific Charge, Speed and the Radius of Trajectory of Electrons
Fizikos laboratorinis darbas. Observation of the Movement of Electrons in Electric and Magnetic Fields, the Determination of the Specific Charge, Speed and the Radius of Trajectory of Electrons. Purpose. To observe the trajectories of electrons moving with different speeds in magnetic fields of various inductions. To determine the specific charge of an electron. To determine the magnitude of magnetic induction causing the different radii trajectories of electrons. To determine the speed of electrons circling at different radii in a magnetic field. Apparatus. The main formulas. Procedure. Tables of measurement data. Conclusions. References.
Helmholtz coil, electronic tube filled with rarefied argon gas, direct current source, ammeter and voltmeter.
Figure 1. Setup for observation of the movement of electrons in electric and magnetic fields: 1 – Helmholtz coils for producing magnetic field; 2 – electronic tube in which the flux of electrons is produced and the movement of electrons is observed; 3 – the source of direct current (DC) for producing magnetic fields inside of the coils; 4 – ammeter for measuring the current strength in the windings of the coils; 5 – the source of steady voltage for acceleration of electrons; 6 – voltmeter for measuring the voltage accelerating electrons.
Figure 2. Electronic tube. 1 – the source of electrons (electrons’ “projectile”), 2 – “ladders”.
Task I. to get to know the setup and its connection to the mains and observe the trajectories of electrons:
Plug the source of electric current 3, the source of voltage 5, ammeter 4 and voltmeter 6 into the mains of an alternating voltage (the switches of the current and voltage sources are on the black side of the devises).