a. Singly ionized calcium ions Ca+ (charge +e) move to the right while free electrons move to the left through the same narrow tube. At a certain section, 2.5×1016 ions pass per second to the right and 4.0×1015 electrons pass per second to the left.
(i) Find the magnitude and direction of the net electric current at that section.
b. (ii) If the electron rate suddenly doubles while the ion rate remains unchanged, by what percentage does the magnitude of the net current change?