Final answer:
Energy lost during transmission is directly proportionate to the square of the current due to Joule losses.
Step-by-step explanation:
The energy lost in a transmission is directly proportionate to the square of the current in the transmission wires, due to Joule (or I2R) losses. This energy loss manifests as heat produced by the resistance of the wires (Rwire). To reduce energy loss during transmission, it's common to transmit at a higher voltage and lower current, hence why long-distance transmission lines operate at higher voltages, often in the range of hundreds of kilovolts.