Voltage and Electric Current
Voltage and electric current is the push and flow of tiny charges through a wire.
A water tank sits high on a shelf, with a pipe running down to a wheel below. The height of the tank is the voltage — it gives water the push to flow downward. The water moving through the pipe is the electric current. A taller tank means more push and faster flow, just like higher voltage drives more current through a wire.
Explaining voltage and electric current by grade level
A battery gives a push. That push moves tiny bits through a wire. More push means more bits flow. You can see this work when a bulb lights up.
Projects that explore voltage and electric current
Each station has a thumbtack switch and a light connected by wire to a battery. When you press the switch, the circuit closes and the battery provides a push that moves charges through the wire. That push drives current from one station to the other, turning the light on. Release the switch and the light goes off — the circuit opens and the flow stops.
Voltage and electric current is the push and flow of tiny charges through a wire. You can measure this push and flow when you attach wires from the meter's probes to the metal strips, and measure the voltage and current.
Before testing, you rub each copper, zinc, and lead sheet with sandpaper to remove any deposits. Each metal then sits in its own nitrate solution, with a porous cup separating the two halves of the cell. When you connect wires to the voltmeter, the reading shows the push driving tiny charges through the wire. Different metal pairings produce different amounts of that push — so as you switch between zinc-copper, zinc-lead, and copper-lead, the voltmeter reading changes with each combination.
A galvanic cell works by placing two different metals in separate sulfide solutions and connecting them with a salt bridge that lets charge flow between them. The size of the push driving those charges through the wire depends on which metals you pair. Testing lead-copper, copper-zinc, and zinc-lead with a digital voltmeter reveals the difference clearly: the lead-copper pair generates the highest voltage at 0.473 V, while the zinc-lead pair produces the lowest at 0.049 V.