Question

Gases are generally maintained at very low pressures in a cathode ray tube:

• A. To prevent collision between the atoms of the gas to form ions
• B. To slow down the speed of a moving atom to show phosphorescence
• C. To slow down the speed of moving ions to accept an electron
• D. So that there is enough space for the electrons to accelerate and produce more electrons.

Answer 1

The correct option is D So that there is enough space for the electrons to accelerate and produce more electrons.

In the cathode ray tube experiment, the gas is maintained at a very low pressure up to ${10}^{-3}$ mm Hg, so that there is enough space for electrons to accelerate before colliding with more atoms, ejecting a large number of free electrons.