Potential divider and potentiometer sim
Drag the sliding contact of a real slide rheostat used as a potentiometer (or choose R1 and R2 on a two-resistor board), measure V_in and V_out with a digital voltmeter, record V_out against the contact's position in an empty table, see your own points make a straight best-fit line through the origin, and check V_out = V_in × R2 ÷ (R1 + R2) against your readings; a load across the output (beyond the syllabus) bends the line.
Practical electricity: the potential divider and the potentiometer · covers the O-Level, IGCSE topic
What the sim shows
Model. Every p.d. comes from one nodal-analysis solver shared by the circuit figures. Supply: 0 to 6 V in 0.5 V steps, internal resistance 0.5 Ω (chosen). Each lead 0.01 Ω; bars, clips and the sliding contact taken as perfect conductors. Slide rheostat 20 Ω over a 200 mm winding, rated 2 A, taken as perfectly uniform, so the part from A to the contact is 20 Ω × x ÷ 200 mm; the contact moves in whole millimetres (the scale reads to 1 mm). The 200 mm scale and pointer are added for this practical; a real slide rheostat has neither. Fixed resistors marked 10, 22, 47, 100 Ω, rated 1 W, ±5 %: each true value is drawn evenly within ±5 % of its marking by a seeded generator, a new batch on each load (chosen). Load resistors (beyond the syllabus) 100 and 20 Ω, rated 1 W, taken as exact. Digital voltmeter 20 V range, reads to 0.01 V, 10 MΩ (chosen typical values). Steady d.c.: nothing warms up or drifts.
- The sliding contact (or, with two resistors, the one you chose)
- Power supply, switch, voltmeter, slide rheostat with scale, two-resistor board, load stand
Use it in your lessons
- Try it here: anyone can unlock 2 figures free, and a free account unlocks up to 5. Runs on a laptop, a Chromebook or a phone; nothing to install.
- Present it and share student links with the teacher plan, from US$5 a month, billed yearly.
- Put it on your own website or LMS for US$9, paid once, or every sim from US$29 a month.
Free guide: 12 practicals as sims, and how to run one in a lesson →
Need a version for your exact set-up? Have one made: US$49 a figure in an order of 5.
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