Copper has an electrical resistivity %u03C1 = 1.72 x 10-8 %u03A9m.
(a) What is the electrical resistance of a copper wire with a radius of 1.0 mm and a length of 25 m?
(b) If this wire is used in an extension cord to connect a device that draws a current of 1.0 A, how much power is dissipated in the wire?