His apprentice, Maya, scrolled through her phone. "The spec sheet says the pump is 200 metres from the battery shed, Jack. We used 6mm² cable."
Jack reached into the glove box and pulled out a crumpled, dog-eared piece of paper. On it was a hand-drawn table:
"Bingo. We didn't just fry the pump. We fried two thousand dollars' worth of buried copper, too."
$$V_d = \frac2 \times L \times I \times \rhoA$$