The Electron Gun

Question 1

What is an electron gun?

Answer 1

An electrical device used to produce a narrow beam of electrons.

Question 2

Describe the process of the electron gun producing high-speed electrons.

Answer 2

•Electrons are emitted from the hot wire/filament at the rear of the electron gun.
•There is a large p.d. between the filament and an anode.
•Electrons are accelerated towards the anode.
•They pass through a hole/gap in the anode.

Question 3

What is thermionic emission?

Answer 3

The emission of electrons through the action of heat.

Question 4

If there is work done on an electron, what does that equal to?

Answer 4

The gain in kinetic energy

•eV=1/2mv^2

Question 5

What does the formula in the gain of kinetic energy assume?

Answer 5

The electrons have negligible kinetic energy at the cathode.

Question 6

What is the value of the mass of an electron?

Answer 6

9.11*10^-31 kg

Question 7

What is the value of the charge of an electron?

Answer 7

1.6*10^-19 C