Litmux Studio

LabOhm's law · 15 min

Lab: Ohm's law on the bench

Measure a current with the multimeter in series, then change the resistance and the voltage and watch Ohm's law work: I = V / R.

The circuit for: Lab: Ohm's law on the bench
The circuit you start with

The steps

  1. Press RUN. Nothing flows yet: the loop is open between R1's bottom end and the 0 V ground symbol below it. (Every ⏚ is the same 0 V point.)RUN is on the toolbar (F5).
  2. Put the multimeter in the gap. Place the Multimeter, turn its dial to A⎓, wire its 10A socket (red) to R1's bottom end and its COM socket (black) to the ground symbol below. The current flows through the meter: I = 9 V / 1 kΩ = 9 mA.A current meter goes IN the loop - in series - so the current has to pass through it. For current the red lead goes in the A socket.
  3. Double-click R1 and make it 2.2k. Predict first: I = 9 / 2.2 = 4.1 mA.More resistance, less current - in proportion.
  4. Now halve the voltage: double-click the battery and set it to 4.5 V. The current halves too: 4.5 / 2.2 = 2.0 mA.Half the push, half the flow.
  5. Your turn to predict: what does R1 = 470 Ω give at 4.5 V? Work it out, then set R1 and check the meter (about 9.6 mA).I = 4.5 V / 470 Ω.

What it shows