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The experiment used a 1 ohm resistor to act as a load in order to quickly discharge the hydrogen
from the fuel cell's balloon. But the reading indicated 2.4 ohms. So where did the extra
resistance come from?
Recall that there is another 1 ohm sense resistor in the circuit that adds to the total resistance.
So the 1 ohm load added to the 1 ohm sense resistor is 2 ohms.
But what about the extra 0.4 ohms – where did it come from?
This inaccuracy is caused by the fact that the load resistor is not exactly 1 ohm...it could be a
little more or less depending on how it was made at the factory. Plus, the way it is connected to
the Data Acquisition Card could add a little more resistance to the circuit. If it was attached
loosely (like it was in this experiment) the connection could add some resistance.
You will experience more readings like this in the other experiments, so pleased be prepared for it.
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