What is cathode rays?. These are streams of electrons emitted at the cathode of an evacuated tube containing an anode and a cathode.
Production of cathode rays
They are produced by a set up called a discharge tube where a high voltage source usually referred to as extra high tension (EHT) supply connected across a tube containing air at low pressure thereby producing a luminous electron discharge between the two brass rods placed at opposite ends of the tube. These electron discharges are called cathode rays which were discovered by J.J Thomson in the 18th century.