As you increase the current flow inside the coils the field becomes stronger causing the beam to curve according to Flemings LH rule of FBI. He then setup a magnetic field at 90 degrees to the beam using coils of wire (Helmholz coils). You can see at the start of my video how the spot on the glass tube is the impact of the electrons causing fluorescent on paint on the inside of the tube. He accelerated a beam of electrons in a glass tube. Then Jean-Baptiste Perrin conducted a very simple but very clever experiment. He agreed with his teacher that they must be electromagnetic waves. Since molecules of gas could not go through the foil, Lenard knew that cathode rays could not be charged molecules. The cathode rays went right through the foil. Hertz’s student, Philipp Lenard, designed a cathode ray tube with a thin foil at one end. Hertz concluded that the cathode rays were a new kind of electromagnetic wave. When Hertz connected his tube to the battery, the cathode rays kept going in a straight line. Negatively charged molecules should have been attracted to the positive plate. One plate was positively charged and the other was negatively charged. He set a cathode ray tube between two metal plates. The German physicist Heinrich Hertz tested this hypothesis. If cathode rays were streams of charged particles, an electric field also should have deflected their path. Since a magnetic field caused cathode rays to move in a circle, Crookes reasoned, they must be made of charged particles. Crookes knew from the laws of electricity and magnetism that a charged particle in a magnetic field would move in a circle. The English scientist William Crookes thought cathode rays were streams of molecules that had picked up a negative electric charge. The German physicist Eugen Goldstein named them “cathode rays.” Hittorf concluded that the cathode was emitting something that travelled in straight lines, like light rays. Plucker’s student, Johann Wilhelm Hittorf, put solid objects inside the tube between the cathode and the glow. When Plucker held a magnet near the tube, the glowing spot moved. He noticed that the glass near the cathode glowed with greenish light. He attached the other electrode, the cathode, to the negative terminal. Plucker attached one electrode, called the anode, to the positive terminal of a battery. Geissler’s friend Julius Plucker used the pump to evacuate a special kind of tube. With the pump he could remove almost all of the air from a sealed glass tube. In that year, Heinrich Geissler invented the mercury vacuum pump. The story of cathode rays begins in 1855. Diffusion in Solids, Liquids, Gases and Jelly.KS3 Energy Conduction, Convection and Radiation.What Causes an Eclipse of the Moon – the Ecliptic!.8 Astrophysics – Part C “Stellar Evolution”.Chernobyl and Radiation in the Food we Eat.7 Radioactivity and Particles – Part C “Fission and Fusion”.7 Radioactivity and Particles – Part B “Radioactivity”.7 Radioactivity and Particles – Part A “Units”.6 Magnetism – Part C “Solenoids and Fields”.6 Magnetism – Part B “Magnets and Electromagnets””.5 Solids Liquids Gases- Part D “Ideal Gases”.5 Solids Liquids Gases- Part C “Change of State”.5 Solids Liquids Gases- Part B “Density and Pressure”.Cheese Rolling – Gravitational Potential Energy to Kinetic.4 Energy – Part D “Energy and Human Influences”.4 Energy – Part C “Work Energy and Power”.3 Waves – Part C “Electromagnetic Spectrum”.2 Electricity – Part D “Electrical Charge – Static”.2 Electricity – Part C “Energy and Voltage”.1 Forces and Motion – Part C2b “Momentum and Moments”.1 Forces and Motion – Part C2a “Movement F = ma, Terminal V, Stopping Distances”.1 Forces and Motion – Part C1 “Shape and Hookes Law”.
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