Question 10
FA student investigates how the resistance of a nichrome wire depends on the length of wire used. The wire is kept at a constant temperature. Figure shows the student's results.
Figure: The resistance of a nichrome wire plotted against the length of wire used
a.[1]
Give the resistance of 70 cm of the wire. Use Figure.
b.[1]
One of the plotted points in Figure 2 is anomalous. Give the length of wire at which the anomalous result was obtained.
c.[2]
Describe the relationship between the resistance of the wire and the length of wire used.
d.[2]
Explain why the temperature of the wire must be kept constant during the investigation.
e.[1]
Give one way the student could keep the temperature of the wire constant.