Observation of the movement of electrons in electroc and magnetic fields
Fizikos laboratorinis darbas. Observation of the movement of electrons in electroc and magnetic fields , the determination of the specific charge, speed and the radius of trajectory of electrons.
The electric tube consists of a glass vessel which is evacuated and filed with rarefield noble argon gas at the pressure of 1 pa. In the right side of it the electronic lamp is arranged , in which due to thermionic emission electrons are produced and accelerated by anodic voltage that can be changed. In the tube two metal strips firmed up with metal stics 2 cm apart from one to another are arranged. This arrangement is similar to horizontal „ladders“ at the distance of 4cm from the first stick the above mentioned electric lamp shooting electrons vertically up is arranged. The electronic tube is placed midway between two parallel helmholtz coils which produce magnetic field when a current is let to flow along their turns. Each coil has 150 turns, the coils are at the distance r=2 m, equal to the average radius of a coil, one from other.
The magnitude of magnetic induction produced by two helmholtz coils, each of them of radius r , midway between their centers, which is at the distance 5r from the center of each coil when the current of the same magnitude and direction flows along their turns is.