Circuit Builder

Part A — Building a series circuit

1. Drag a Cell, two Fixed Resistors and an Ammeter onto the canvas, then draw wires so all four components form a single loop, one after another.
2. Drag a Voltmeter onto the canvas and wire its two leads across one of the resistors (the same two points that resistor connects to, not into the main loop).
3. Read the ammeter, then click and drag the ammeter to a different point in the loop and read it again. What do you notice about the current at different points in a series circuit?

Part B — Building a parallel circuit

1. Click 'Clear Circuit', then build a cell connected to two resistors that branch off from the same two junctions, so each resistor forms its own loop back to the cell.
2. Add an ammeter in the main loop next to the cell, and a second ammeter in just one of the branches. Add a voltmeter across each resistor in turn.
3. Record the main current, each branch current and each resistor's voltage. How does the main current compare with the sum of the branch currents, and how do the voltages across the branches compare?

Part C — Comparing the rules

1. Select a resistor and use the Component Value slider to change its resistance. Watch how the readings change in both your series and parallel circuits.
2. Select a component and click 'Rotate Component' (or right-click it on desktop) to rotate it 90°, and check the readings stay the same — rotating a component shouldn't change any measurement.
3. Using your results from Parts A and B, write one rule for how current behaves in a series circuit and one for a parallel circuit. Do the same for voltage.