Four layer coaxial cylindrical electrodes are used U = 200kV, r1 = 2cm, r2 = 3.5cm, r3 = 5cm, r4 = 7cm, R = 10cm, r1 = 12.9, r2 = 6, r3 = 4, r4 = 2.2;

A) Draw a four-layer coaxial cylindrical electrode system on a scale.

B) Calculate the maximum and minimum field strength in the layers.

C) Find the tensions falling on the layers.

D) If R = 10cm and r4 = 8cm, explain by calculating the radii of r1, r2, r3 and layer thicknesses to create a system that provides the condition that the area should be smooth.