Current Control
Turn the voltage up, squeeze the resistance and watch electricity flow like water in a pipe. Seven missions on Ohm's law, from a lamp to a safe LED.
First flow
The pipe is 10 ohms wide. Turn up the voltage until the lamp glows normally: about half an amp (0.4 to 0.6 A).
Resistance: 10 Ω (fixed for this mission)
- Voltage
- 0V
- Resistance
- 10Ω
- Current (meter)
- 0.00 A
- Gadget
- off
Current = voltage ÷ resistance. 100% is the brightness the gadget is made for.
The science behind it
Read these after a few missions.
Voltage: the push that moves electricity
Voltage is the push a battery gives to electricity, like pressure in a water pipe. See what volts measure and why more push means more flow.
Current: how much electricity flows
Current counts how much charge passes a point every second. Learn what an amp is, why electrons drift slowly, and why a bulb lights up at once.
Resistance: what slows electricity down
Resistance is how hard it is for electricity to get through. See why thin wires heat up, what a resistor does and why metals conduct.
Ohm's law: how push, flow and squeeze connect
One short rule links voltage, current and resistance. Work out any of the three, and use it to protect an LED.
Using Current Control in class
Missions 1 and 2 isolate one variable at a time: voltage with resistance fixed, then resistance with voltage fixed. Mission 3 shows proportionality, and Mission 4 shows that many voltage–resistance pairs give the same current. Mission 5 introduces a resistor as protection, Mission 6 is the classic LED resistor calculation, and Mission 7 asks students to use R = V ÷ I to find a hidden value. The pipe is drawn from the real numbers, and the meter always shows V ÷ R. Read the Ohm’s law lesson.