Question

Origin of cathode rays?

Answer 1

In 1897, British physicist J. J. Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, which was later named the electron.Cathode ray tubes (CRTs) use a focused beam of electrons deflected by electric or magnetic fields to create the image on a television screen.

Answer 2

origin of cathode rays:-)

■ JJ Thomson first discovered presence of electron by use of discharge tube [this can be seen in attachment]

■ discharge tube made up by hard glass and have 60 CM length.

■ the tube is connected with a vacuum pump which can regulate the pressure of gas. as we know at high pressure gases are poor conductor of heat and electricity but when we decrease pressure up to the range of

${10}^{ - 2} atm$

they become good conductor.

■ discharge tube fitted with two metallic rod one is anode and another is cathode to explain path of ray we should use porous anode where cathode rays travel from cathode to anode and strike on zinc sulphide screen to give when yellow green colour .