Volta potential by its work function, and so dissimilar metals can show an electric potential difference even at equilibrium. The Volta potential is "not" an intrinsic property of the two bulk metals under consideration, but rather is determined by work function differences between the metals' surfaces. Just like the work function, the Volta potential depends sensitively on surface state, contamination, and so on. The potential is given by the formula: formula_1, where V is the potential, The Volta potential can be significant (of order 1 volt) but it cannot be measured directly by an ordinary voltmeter. A voltmeter does not measure vacuum
Inductance to the lower voltage end. The energy from the external circuit required to overcome this "potential hill" is being stored in the increased magnetic field around the conductor. Therefore, any inductance with a current through it stores energy in its magnetic field. At any given time formula_21 the power formula_22 flowing into the magnetic field, which is equal to the rate of change of the stored energy formula_23, is the product of the current formula_3 and voltage formula_20 across the conductor From (1) above When there is no current, there is no magnetic field and the stored energy is zero.