The magnetic field deflects the cathode ray. Now he applied a magnetic field across the cathode ray tube by using an external magnetic field. He had already deduced that the particles were negatively charged.įirstly, he applied an electric field in the path between anode and cathode and measured the deflections from the straight path. Then, he performed the third experiment to know the particles’ nature and reduce the particle’s mass as they had too small of a mass to be calculated directly.įor the experiment, he used the cathode ray tube with a high applied potential difference between the two electrodes, with the negatively charged cathode produced the cathode rays. This proved that the cathode rays were negatively charged. When the charged metal plates were introduced, he found that the cathode rays bent away from the negative plate and towards the positive plate. Instead of an electrometer at one end of the Cathode Ray Tube, he used a fluorescent-coated tube that would glow were the cathode ray hit it. He put a negatively charged metal plate on one side of the cathode rays to go past the anode and a positively charged metal plate on the other side. Then, he conducted a Second experiment to prove the charge carried by the cathode rays was negative or positive. He deduced that the electric charge and the cathode rays must be combined and are the same entity. The metal had two small diversions(slits), leading to an electrometer to measure small electric charges.įrom the first experiment, he discovered that the electrometers stopped measuring electric charge. He built his cathode ray tube with a metal cylinder on the other end.

Thomson conducted his first cathode ray tube experiment to prove that rays emitted from an electron gun are inseparable from the latent charge. J.J.Thomson conducts three experiments with cathode ray experiment.

In jj thomson cathode ray experiment