Thus, to drive a device of power P, the power wasted in the
connecting wires is inversely proportional to V 2 The  transmission cables
from power stations are hundreds of miles long and their resistance Rc is
considerable To reduce Pc, these wires carry current at enormous values
of V and this is the reason for the high voltage danger signs on transmission
lines — a common sight as we move away from populated areas Using
electricity at such voltages is not safe and hence at the other end, a device
called a transformer lowers the voltage to a value suitable for use