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Temperature dependence of resistance

(a) A 5 m length of copper wire at 20°C has a radius of 0.25mm. If a potential difference of 10V is applied across the length of the wire, determine the current in the wire.

(b) If the wire is heated to 50.0°C and the 10 V potential difference is maintained, what is the resulting current in the wire?

Solution Preview

a) We can use Ohm's law to determine the current for V = 10 V.

For copper resistivity, r = 1.7à?10^-8 Ohm m,

The resistance is,

R = rl/A ...

Solution Summary

Detailed explanations included.

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