An experiment is done to verify that the potential difference across a conductor is directly proportional to the current in the conductor if the temperature stays constant.
Four cells, each with an emf of 1,5 V, are connected in series with an ammeter, switch S and a combination of a resistor R and resistors of 4 Ω and 6 Ω, as shown in the diagram.
Voltmeters V1 and V2 are connected across the battery and the parallel resistors respectively. The internal resistance of the battery and wires are negligible.
10.1 Which law is represented by the underlined phrase above? (1)
The switch is now closed and six resistors (R1–R6), each with a different resistance, are placed in the place of R, one at a time. The voltmeter and ammeter readings are recorded. The results are as follows:
10.2 Use the attached graph paper and draw a graph of potential difference versus current using the data in the table. (4)
10.3 What does the gradient of the graph represent? (1)
10.4 If voltmeter V2 is only connected across the 4 Ω resistor, how will the gradient of the graph change? Write down only INCREASES, DECREASES or STAYS THE SAME. (1)
10.5 If the 4 Ω resistor is removed, how will the gradient of the graph change?
Write down only INCREASES, DECREASES or STAYS THE SAME. (1)
10.6 Calculate the resistance of resistor R3 using the values in the table. (5)
10.7 Calculate the energy dissipated in resistor R4 in 10 seconds. (3)
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TOTAL: 150