An aluminium wire long is connected in parallel with a copper wire long

PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits

Problem

An aluminium wire

7.5\text{ m}

long is connected in parallel with a copper wire

6\text{ m}

long. When a current of

5\text{ A}

is passed through the combination, the current in the aluminium wire is

3\text{ A}

. The diameter of the aluminium wire is

1\text{ mm}

. Determine the diameter of the copper wire. The resistivities of copper and aluminium are

0.017\,\mu\Omega\,\text{m}

and

0.028\,\mu\Omega\,\text{m}

, respectively.