TwiddleLab / Courses / Physics
Circuits You Can Build
Lessons
- Close the Loop (5 min): A bulb lights only in a closed loop: from the battery's + end, through the bulb, and back to its minus end.
- Current: Charge on the Move (7 min): Current is how much charge passes a point each second: I = Q ÷ t.
- Voltage: The Push Behind the Flow (7 min): Voltage is the energy each coulomb of charge gets from the battery: 1 volt = 1 joule per coulomb.
- Resistance and Ohm's Law (7 min): Resistance (R) is how hard a part makes it for current to flow. It is measured in ohms (Ω).
- Series: One Path (7 min): In series there is one path: the same current flows through every part, and one break stops them all.
- Parallel: Many Paths (7 min): In parallel each branch is its own path to the battery: every branch gets the full battery voltage.
- Power and Your Bill (7 min): Electric power is how fast energy is moved: P = V × I, in watts.
- Short Circuits, Fuses and Safety (7 min): A short circuit is a path with almost no resistance: the current shoots up, wires heat up, and the parts it bypasses go dark.
- Sensors: Resistance That Changes (7 min): An LDR has less resistance in brighter light; a thermistor (NTC) has less resistance when hotter.
- Project: Smart Night Light (8 min): An LED needs a series resistor: R = (V_battery - 2 V) ÷ current.
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