 # GCSE Standard Questions: Electric Circuits Q2. A student investigated how the resistance of a piece of nichrome wire varies with length. The diagram shows part of the circuit that the student used. Copy the circuit in the space below, adding an ammeter and a voltmeter so that the resistance of the wire can be calculated. Be careful to use the correct symbols.

[3 marks]

(b) Describe how the student would obtain the data needed for the investigation. Your answer should include a risk assessment for one hazard in the investigation.

[6 marks]

(c) Why would switching off the circuit between readings have improved the accuracy of the student's investigation?

Tick one box.

 Reason Tick here The charge flow through the wire would not change. The potential difference of the battery would not increase. The power output of the battery would not increase. The temperature of the wire would not change.

[1 mark]

(d) The students used crocodile clips to make connections to the wire.

They could have used a piece of equipment called a 'jockey'.

The photo below shows a crocodile clip and a jockey in contact with a wire. How would using the jockey have affected the accuracy and resolution of the student's results compared to using the crocodile clip?

Tick two boxes.

 Reason Tick here The accuracy of the student's results would be higher. The accuracy of the student's results would be lower. The accuracy of the student's results would be the same. The resolution of the length measurement would be higher. The resolution of the length measurement would be lower. The resolution of the length measurement would be the same.

[2 marks]

(Total 12 marks) 