Hen a thin copper wire that is 178 m long is connected between a 1.2-v potential difference, a current of 2.0 amps flows through the wire. what is the diameter of this wire? the resistivity of copper is 1.72 × 10-8 ω • m.

The resistance of the cylindrical wire is .

Here is the resistance, is the length of the wire and is the area of

cross section. Since the wire is cylindrical .

From the above 2 equations,

The resistance of the wire is given by

Thus, the diameter of the wire is

The diameter of the wire is

answer; equivalent to a one(1) horsepower motor;

this could be newton#'s law of cooling. the cooling curve is exponential