State the relationship between the current and the p.d. for the metal wire.
State how the graph indicates that the temperature of the wire does not change in the experiment.
A second wire made from the same material has the same length as the original wire, but its cross-sectional area is only half as large. Compare the resistance of the new wire and the original wire.
On Fig. 10.1, draw the graph for the new wire.
Three resistors are connected to a d.c. power supply, as shown in Fig. 10.2. The electromotive force (e.m.f.) of the power supply is $6.0\,\text{V}$. Calculate the total resistance of the circuit.
Calculate the current delivered by the power supply.
Calculate the potential difference across the $20\,\Omega$ resistor.
The d.c. power supply is a battery containing several cells. Each cell has an electromotive force (e.m.f.) of $1.5\,\text{V}$. State what the electromotive force (e.m.f.) of a cell means.
In the space below, draw a diagram showing how four of these cells are connected to make a battery of e.m.f. $6.0\,\text{V}$. Mark the positive terminal of the battery.
In a different arrangement for producing a battery of e.m.f. $6.0\,\text{V}$, eight cells of e.m.f. $1.5\,\text{V}$ are connected. In this arrangement, some cells are in series and others are in parallel. In the space below, draw a diagram to show how the eight cells are connected to make the battery.
State one benefit of using a battery made from cells in parallel instead of a single cell.