Isn't the resistance of a wire usually modeled as a constant value? Power dissipated in the wire as heat is proportional to the square of the current. It's equ

Isn't the resistance of a wire usually modeled as a constant value? Power dissipated in the wire as heat is proportional to the square of the current. It's equal to the voltage drop times current (P = I * V). Voltage drop is current times resistance (V = I * R). So P = I^2 * R.