An electrical cable consists of 125 strands of fine wire, each having resistance. The same potential difference is applied between the ends of each strand and results in a total current of 750 mA. (a) We have to find the current in each strand; (b) the applied potential difference; and (c) the resistance of the cable.

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(a)

The given electrical cable consists of 125 strands of wire. Resistance, r, of each strand is

The total current flowing through the cable is

Therefore, current flowing in each strand of wire will be

(b)

As the resistance of each strand of wire is

the potential difference across each strand will be

(c)

The resistance of the cable will be