- #1
PFuser1232
- 479
- 20
The power dissipated in a resistor of resistance ##R## with current ##I## passing through it is ##I^2 R##. We can write ##R## as ##\rho \frac{L}{A}## where ##L## is the length of the wire and ##A## is the cross sectional area of the wire. Clearly, increasing ##A## decreases ##R##. Why is less heat dissipated in thicker wires, though? I thought changing the resistance of the wire changes the current passing through it as well. How can we guarantee from the equation ##P = \frac{\rho L I^2}{A}## that increasing ##A## decreases ##P##? Isn't ##I## functionally dependent on ##R##?