# Internal resistance coursework

## Internal resistance of a potato

This was because I could plot a graph and show the general trend. Hence: V 5. I will also ensure that there is a clear indication that the power is isolated by means of a switch and an L. Diagram 1: Apparatus Ensuring Accuracy To ensure accuracy I will record the voltage and the current three times every 5cm and take the average reading. Calculate: a the potential difference across each lamp; [3] b the resistance of each lamp. In addition, I will make sure I turn the power pack off after each reading. Discussion Overall, my results are very consistent with my predictions. Each resistor has a resistance R. Tip You can always quickly redraw the circuit so that you can visualise the series and parallel sections of the circuit.

This confirms the first part of my prediction: that the longer the wire the larger the resistance. I will repeat this method every 5cm until I get up to cm, taking three readings from both the voltmeter and ammeter each time to ensure accuracy.

The total p. The power dissipated by each lamp is 60 W and the total current drawn from the supply is 1.

This would have prevented the area of the wire from remaining constant and would have affected my results. In addition, my prediction that doubling the length of the wire increases the resistance by a factor of two is correct see Table 4.

What is the current in each resistor?

Tip You can always quickly redraw the circuit so that you can visualise the series and parallel sections of the circuit. However, due to my line of enquiry, I will only change the length of the wire. However, using new pieces of wire each time would have been too impractical and time-consuming in the context of this lesson.

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