The Laplacian of this quantity is equal to minus the charge density divided by the permittivity of free space.
The Laplacian of this quantity is equal to minus the charge density divided by the permittivity of free space. In one system, this quantity is equal to the current times the magnetic field divided by the product of the plate thickness, electron charge, and density of mobile charges--that quantity arises due to a magnetic field perpendicular to an electric current in the Hall effect. Transformers can step-up or step-down this quantity, which is proportional to the time derivative of the current for an inductor and to the charge stored for a capacitor. For 10 points, name this quantity defined as the electric potential energy per unit charge and equal to the current times the resistance by Ohm's Law.
The Laplacian of this quantity is equal to minus the charge density divided by the permittivity of free space.
voltage [accept electric potential, accept any answers referring to a change in voltage or a voltage drop]