Power Transmission

Electrical energy is transmitted over long distances through power lines. A major problem is energy loss due to resistance in the transmission wires.

Heating loss is: **P_loss = I²R** This equation shows that transmission loss depends strongly on current.

For transmitted power: **P = VI If power `P` is fixed, increasing voltage allows current to decrease. Lower current greatly reduces: I²R losses**

At a power station: step-up transformer → high voltage, lower current Near consumers: step-down transformers → safer/useful lower voltages

Suppose power must be transmitted. If current is reduced to half: **P_loss ∝ I² so loss becomes: (12)² = 14** of the original loss.

Real transmission cables have finite resistance. Engineering aims to reduce losses using: high transmission voltage; suitable conductors; * appropriate cable dimensions.