Question: a cylindrical copper wire of the length 140 m and...
A cylindrical copper wire of the length 14.0 m and a diameter of 2.00 mm is coated with 1 mm of aluminium so that the diameter of the composite wire is 3 mm. The composite wire is connected between the terminals of a power supply of potential difference 12 V.
(a) Find the resistance of the Cu wire without the Al coating.
(b) Find the resistance of the Al part of the wire without the Cu core.
(c) Find the resistance of the composite unit? (Hint: decide whether the aluminum and copper parts of the pipe are in series or in parallel.)
(d) Find the currents through the Al and Cu parts of the wire. Find the total power drawn from the circuit.