Voltage
Voltage is the push that moves energy through a wire, like water pressure moves water through a hose.
A tall jar of water has more pressure at the bottom than a short jar. That pressure pushes water out faster when you open a tap at the base. Voltage works the same way — it is the push that moves electric charge through a wire. A higher voltage means a stronger push, just like a taller jar gives a stronger flow.
Explaining voltage by grade level
A lemon can work like a small battery. Two different metals stuck into the lemon create a push. That push moves energy through a wire. The bigger the push, the more work the energy can do.
Projects that explore voltage
A potato contains moisture and acid that react differently with two metals — copper and zinc, for example. That chemical reaction creates a small push that moves energy through the wire, the same way water pressure drives water through a hose. Wire enough potatoes in series and their voltages add together, producing enough current to light a low-power LED.
Wind insulated wire around a hollow box and spin magnets inside it, and the changing magnetic field creates a current. When you compare coils wound at 150, 300, and 450 turns, a digital voltmeter shows something clear: the more turns, the higher the voltage reading. That's the push at work — more wire in the coil means a stronger push moving energy through the circuit.