Answer the following questions. 300 word of each question and a reference of them.
1. Why does the final electron energy not depend on the grid voltage?
2. Can you think of a reason as to why the cathode is not directly heated by current?
3. Do you think the electrons emitted from the cathode with zero velocity, one velocity, or a range of velocities? Hint: The electrons inside the metal that are able to escape are a bit like a gas of molecules at finite temperature.
4. The coils are connected in series. Why would connecting them in parallel be a bad idea?