Figure 1 below shows two circuits X and Y that were used by a student to test a battery of
four identical cells. In circuit X there was no load resistor and in circuit Y a load resistor was connected. You can assume that the meters in the circuits are ideal.
Figure 1
Explain why there is a difference in voltages recorded in the two circuits.
Calculate the internal resistance of a single cell.
One of the cells in the battery is reversed.
Determine the new reading on the ammeter in circuit Y.
In circuit Y, the resistance of the load resistor R is altered so that a series of values on the voltmeter and the corresponding values of the current on the ammeter are obtained.
Figure 2
Using the axes in Figure 2, sketch the graph you would expect to obtain as R is changed. State how the values of ∈ and r can be obtained from the graph.
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