Compute the voltage drop along a 24-m length of household no. 14 copper wire (used in 15-A circuits). The wire has diameter 1.628 mm and carries a 13-A current. The resistivity of copper is 1.68*10-8Ω⋅m.

We know that the formula for resistance in terms of length and area is given by

R = p l / a

Where p be the resistivity and a be the area of crossection

a = pi * d^2 / 4

Where d be the diameter

a = 3.14 * (1.628 * 10^-3) ^2 / 4

a = 2 * 10^-6 m^2

R = 1.68 * 10^-8 * 24 / (2 * 10^-6)

R = 20.16 * 10^-2 ohm

By use of Ohm's law

V = IR

V = 13 * 20.16 * 10^-2

V = 2.62 Volt