4. An experiment was performed to investigate the effect of the type of conductor on the
current strength. A 200 mm length of nichrome wire with diameter 0,3 mm is wound
into a coil and attached to a circuit. The potential difference is measured across the
coil. The experiment is repeated for a 200 mm length of copper wire of diameter 0,3
mm. Temperature was kept constant. The following results were obtained:
14)
Current through each wire (A)
0,2 0,4 0,6 0,8 1,0
Potential difference across the nichrome wire (W) 0,8 1,8 2,4 3,2 4,0
Potential difference across the copper wire (V) 0,4 0,8 1,2 1,6 2,0
(1)
(2)
4.1 Write down the independent variable in this investigation
4.2 Which other variables were kept constant besides the temperature?
4.3 Draw graphs (on the same set of axes) on the graph paper provided to
illustrate the relationship between the potential difference across each wire and
the current through the wire.
4.4 Use the graph to determine the resistance of each wire.
4.5 Which wire is the best conductor of electricity? Explain your answer.
(8)
(6)
(3)
[29]
TOTAL = 43