Define the term electric potential difference.
A battery is connected to two resistors X and Y, as shown in Fig. 6.1. The resistance of resistor X is greater than that of resistor Y. State and explain which resistor dissipates more power.
A battery with electromotive force (e.m.f.) $9.0\,\text{V}$ and internal resistance $r$ is connected to two resistors P and Q, as shown in Fig. 6.2. In a time interval of $540\,\text{s}$, a total charge of $650\,\text{C}$ passes through resistor P. Over this interval resistor P dissipates $4800\,\text{J}$ of energy. The current in resistor Q is $4.5\,\text{A}$. Assume that the battery e.m.f. stays constant. Calculate:
the current through resistor P
the potential difference over resistor P
the battery’s internal resistance $r$.
Calculate the current through resistor P.
Calculate the potential difference over resistor P.
Calculate the battery’s internal resistance $r$.