TO FAQ A BATTERY LIGHTS A BULB. WHATS GOING ON THERE?
TO FAQ WHY IS VOLTAGE NOT ELECTRICAL “PRESSURE?” Voltage is “Potential”, and potential is not pressure, even though a potential-difference can “push” upon the electrical charges. Here’s one way to imagine it. Suppose we roll a boulder up a hill. This stores potential energy, and we get the energy back if the boulder rolls back down. Electrostatic fields are like gravity, and VOLTAGE IS LIKE THE HEIGHT OF THE HILL. The higher we go, the more “gravitational potential” we put into the boulder. But height is not pressure, and the hill is still there even when the boulder is gone. In a similar way, we need both voltage and charges before there can be any “electrical pressure.” The voltage only causes a “push” when the charges are present. Voltage can appear in space, but if there are no charges, then no pushing-force or “pressure” exists. This is very different than, say, water pressure. Water can push on the surface of a submarine, but the pressure doesn’t go away when there’s no submarine
