A cell with constant electromotive force (e.m.f.) is connected across a fixed resistor. Over time, the internal resistance of the cell increases. Which change occurs as the internal resistance of the cell increases?
a decrease in the charge of each charge carrier
a decrease in the potential difference measured across the cell
an increase in the energy dissipated per unit time in the fixed resistor
an increase in the number of charge carriers leaving the cell per unit time