Ohm’s Law, explained.
Ohm’s law relates voltage, current and resistance for an ohmic element through V = IR.
Why it happens
A fixed ten-ohm resistor and an adjustable resistor are connected in series or parallel. Equivalent resistance determines source current; electrical power is voltage times total current.
Ohm’s law relates voltage, current and resistance for an ohmic element through V = IR.
Read the result
Equivalent resistance and source current concern the entire selected network; an individual branch need not carry that total current.
A worked example
Reconnect the same two resistors
Set voltage to twelve and adjustable resistance to ten ohms.
Compare series resistance twenty ohms and current 0.6 A with parallel resistance five ohms and current 2.4 A.
Keep voltage fixed while checking why total electrical power rises under the lower equivalent resistance.
OPTIONAL DEEPER DETAILGo deeper: inside the model
Inside this model
A fixed ten-ohm resistor and an adjustable resistor are connected in series or parallel. Equivalent resistance determines source current; electrical power is voltage times total current.
Where this idea is useful
A practical use
Explain why adding a parallel branch can increase the current required from a voltage source.
A common misconception
“Adding another resistor always lowers total source current.”
A parallel path can lower equivalent resistance, increasing current drawn from an ideal constant-voltage source.
What this explanation leaves out
- Ideal ohmic elements at fixed conditions omit heating, supply limitations and component ratings. This teaching circuit is not practical electrical-work guidance.
Can I use these values to select real components?
Actual supplies, heating and component ratings need additional information; this ideal teaching calculation is not electrical-work guidance.
Are you reasoning about a branch resistance or the whole network’s equivalent resistance?
Associated thinkers
Associations marked provisional are awaiting source review.
Further reading
Explore the original research or the teaching reference behind this experiment.