Question

If P and V are the power and potential of device,

the power consumed with a supply potential V

is

Answer 1

Let R be the Resistance of the device

$R=\frac{V^2}{P}\\$

The power consumed with a supply of V is

$P_c=\frac{V^2}{R}\\$

Substitute R in the equation above

$P_c=\frac{V^2}{\frac{V^2}{P}}\\ P_c=P$