Field and Wave Electromagnetics 2nd Edition by David Cheng

Exercise 29

The cathode-ray oscilloscope (CRO) shown in Fig. 3-2 is used to measure the voltage applied to the parallel deflection plates.
a) Assuming no breakdown in insulation, what is the maximum voltage that can be measured if the distance of separation between the plates is h
b) What is the restriction on L if the diameter of the screen is D
c) What can be done with a fixed geometry to double the CRO's maximum measurable voltage