Cathode rays are the invisible rays emerging normally from the cathode of a discharge tube kept at a presence of 0.01 mm of Hg and under a very high potential difference. They are independent of gas used in the discharge tube and their propagation is independent of the position of cathode. Cathode ray can also be called as fast moving electrons.
Properties of Cathode rays
- Cathode rays are emitted normally from the cathode.
- They can penetrate small materials such as thin sheet of aluminum foil.
- They travel in a straight line and cast sharp shadows o object in their path.
- Cathode rays carry negative charge and are deflected by electric and magnetic field.
- Cathode rays have momentum and kinetic energy.
- X-rays are produced when X-rays are suddenly stopped.
- They ionize the gas through they pass.
- They affect photographic plate. –
- They travel with 1/10th the velocity of light.
- Cathode rays produce fluorescence when they fall on certain substances like phosphorus.
- They produce heat when they fall on matter and can exert mechanical pressure.