Voltage is the pressure pushing electricity, current is how much flows, and resistance is a pinch in the wire slowing it. Ohm's law ties the three together: more pressure or less pinch means more flow.
The three quantities of a circuit
Voltage (V, in volts) is the push — the energy per charge that a battery provides. Current (I, in amps) is the flow. Resistance (R, in ohms) is how much the material fights the flow. Ohm's law ties them together in one clean relationship: V = I × R.
More voltage pushes more current; more resistance holds it back. The bulb glows with the current.
Raise the voltage and the current (and the bulb's glow) grows; raise the resistance and the current falls. That is V = IR in action.
Think of voltage as water pressure, current as the flow rate, and resistance as a narrow pipe. More pressure pushes more water; a narrower pipe lets less through. The math is the same.
- A 9-volt battery connects to a 3-ohm resistor. Use V = IR to predict the current.
- Check with the simulation: set voltage to 9 and resistance to 3. Does the reading match your I = 9/3 = 3 A?
- Now double the resistance to 6 ohms. Predict the new current, then verify.
- Write a sentence: when resistance doubles (voltage fixed), current does what?
What you should see: You used Ohm's law to predict a current and confirmed that doubling resistance halves the current.