Power = IV = I2R = V[sup]2[/sup]/R In terms of e.m.f E, of a cell we have IE = I2R = E2/R ∴P1 = E[sup]2[/sup]/R; P2 = E[sup]2[/sup]/R[sub]2[/sub]/E[sup]2[/sup]/R[sub]2[/sub] = E[sup]2[/sup]/R[sub]1[/sub] x R2/E2 = R2/R[sub]1[/sub] ∴P1/P[sub]2[/sub] = R2/R[sub]1[/sub]
