Back to P2 Home

P2: Quiz 4 – Answers

P2: Quiz 4 – Answers

1)

a)

a)

b) We start the experiment by having the wire a certain length (such as 10 cm). We then find the values for potential difference and current. We then make the length of the wire longer (such as 20 cm) and take readings for potential difference and current. We keep repeating the process until we have values for quite a few different lengths of wire. We then obtain the resistance for the different lengths of wire by dividing the potential difference by the current(R = V ÷ I).

c)

i)

c)

i)

ii) The length of wire and the resistance of the wire are directly proportional to each other. We can tell this from the graph because the line of best fit is linear (straight) and it starts from the origin (0)

**Questions**

*Click here for a printable PDF of the circuit, table and graph.*

1) We can undertake an experiment to investigate how the length of a wire affects the resistance of the wire. The diagram below shows an incomplete circuit with a battery and a ruler with two crocodile clips connected to a wire.

a) Add an ammeter to measure the current and a voltmeter to measure the potential difference of the length of wire to the above circuit diagram.

b) Explain how we would undertake the experiment to investigate how the length of wire affects the resistance of the wire.

c) A student completes the experiment and his results are shown in the table below.

b) Explain how we would undertake the experiment to investigate how the length of wire affects the resistance of the wire.

c) A student completes the experiment and his results are shown in the table below.

i) Plot the values from the table for length and resistance on the graph below. Also, add a line of best fit to your graph.

ii) Describe the relationship between length of a wire and resistance. Explain your answer.