E (V/m) 0 2.5 cm B. Cylindrical capacitor: A 1 m long, cylindrical capacitor is made of a metal rod inside of a metal tube as shown in cross section above. The rod has a diameter of 2 cm and the tube has inner diameter 4 cm and outer diameter 5 cm. Determine the capacitance. 1 (cross section) On the axes below, plot the electric field and electric potential as a function of radius, r, assuming that the capacitor is charged to a voltage of 10 V (positive on the inner rod). Calculate and mark the maximum value of each. 2 3 r (cm) (V) 0 1 2 3 r (cm)