Question

Small aircraft often have 24 V electrical systems rather than the 12 V systems in automobiles, even though the electrical power requirements are roughly the same in both applications. The explanation given by aircraft designers is that a 24 V system weighs less than a 12 V system because thinner wires can be used. Explain why this is so.

Short answer

A 24 V system weighs less than a 12 V system because thinner wires can be used since the power consumption is the same so for the higher voltage, a lower current can be used and the total weight of the aircraft can be reduced.

Step-by-step solution

Power consumption of an electric circuit

Power $\left(P\right)$in an electric circuit is exactly equal to current $\mathbf{\left(}\mathbf{I}\mathbf{\right)}$multiplied by voltage $\mathbf{\left(}\mathbf{V}\mathbf{\right)}$.

Compare a 24 V electrical system with a 12 V electrical system

The electrical power requirements of aircraft and automobiles are roughly the same.

Power consumption is

$\mathrm{P}=\mathrm{VI}$

Therefore, a 24 V system weighs less than a 12 V system because thinner wires can be used since the power consumption is the same so for the higher voltage, a lower current can be used and the total weight of the aircraft can be reduced.