A Geiger tube comprises of two elements, a long metal cylindrical shell and a long straight metal wire running down the central axis. Model the tube as when both the wire and cylinder are infinitely long. The central wire is positively charged and outer cylinder is negatively charged. The potential difference among the wire and the cylinder is 1.07 kV. Assume that the cylinder in the Geiger tube has an inside diameter of 3.72 cm and the wire consists of a diameter of 0.538 mm. The cylinder is grounded so its potential is equivalent to zero.
(i) Determine the radius of the equipotential surface which has a potential equivalent to 495 V?
(ii) Determine how far apart are the equipotential surfaces that encompass potentials of 195 and 235 V?
(iii) Compare your outcome in Part (ii) to the distance between the two surfaces that encompass potentials of 680 and 720 V, correspondingly.
What does this comparison tell you regarding the electric field strength as a function of the distance from the central wire?