Potential Divider Lab
Run divider what-if checks with fixed resistors, LDR/NTC placement, optional output loading, and guided prompts on Vₒᵤₜ trends and current.
Find this activity in your course
Learning objectives
- Apply resistance and resistivity, interpret I–V characteristics and explain temperature effects.
- Analyse series, parallel and potential-divider resistor networks.
- Describe variable-potential-divider action
- Describe NTC thermistor action as an input transducer
- Describe light-dependent resistor (LDR) action as an input transducer
- Solve simple NTC and LDR potential-divider problems
A 6.0 volt supply across a resistor R₁ of 2.00 kΩ and a resistor R₂ of 1.00 kΩ. The output p.d. across R₂ is 2.00 volts.
- Vout
- 2.00 V
- R₁ now
- 2.00 kΩ
- R₂ now
- 1.00 kΩ
- Vout as a fraction of the supply
- 0.33
Try this
0 of 4 doneWith two resistors and a 6.0 V supply, make Vout = 2.0 V. (not done yet)
Vout = V × R₂ / (R₁ + R₂), so R₁ must be twice R₂: only the ratio matters.
Make a sensor whose Vout is high in the dark and low in bright light. (not done yet)
In the dark the LDR's resistance is large, so it takes most of the supply p.d. Put it in the arm you measure across.
Make a sensor whose Vout rises as it gets hotter. (not done yet)
The thermistor's resistance falls as it warms, so with it in the top arm the bottom arm takes a larger share.
Connect a load across Vout that pulls Vout down by more than a fifth. (not done yet)
The load is in parallel with R₂, lowering the bottom arm's resistance. A load much larger than R₂ barely changes Vout.