Splitting the Voltage

Interactive Simulator · Voltage Divider

Two resistors in series share the supply voltage between them. The output, taken across the lower resistor, is V_out = V times R₂ divided by (R₁ + R₂), so a bigger share of the resistance takes a bigger share of the voltage. Set the lower resistor to hit a target output, or switch it for a light-dependent resistor and watch the output, and a night-light, respond to the light.

Mission Set R₂ so the output is 4 V (within 0.3 V). Round 1 Streak 0 Best 0

Lower component:

Lower resistor R₂ 3 Ω

The output voltage will be:

Top resistor R₁ is fixed at 6 Ω. Supply is 12 V.

top resistor R₁6 Ω

lower resistor R₂3 Ω

output voltage V_out--

V_out = V × R₂ ÷ (R₁ + R₂) = 12 × 3 ÷ 9 = 4.0 V