U = R IU: V; R: Ω; I: A.
Use when: Ohmic conductor, resistance considered constant.
DC circuits and Ohm’s law
Connect voltage, current, resistance and power in a resistive circuit.
What is happening?
A potential difference can set charges in motion in a closed circuit. An ohmic resistance connects voltage and current by a linear law, in its operating range.
An ammeter is placed in series, a voltmeter in parallel. The model's ideal devices do not disrupt the circuit; Real devices have internal resistances and ratings to respect.
The formulas, with their conditions.
P = U I = R I² = U²/RP: W.
Use when: Power dissipated by the resistance; do not exceed its admissible power.
Where is this principle used?
Industrial electrical workshop
Check sensors, resistors and power supplies.
Electronics manufacturing plant
Sizing resistive elements and controlling cards.
What to observe in the experiment
Double R at constant tension. Compare the current and the dissipated power to their initial values.
References and readings
This sheet explains the principles and their assumptions. Educational simulation can simplify the process; an industrial model requires suitable data and validation.
Have you understood the essentials?
Only one correct answer per question. Answer all three questions, then view the answer key.
Intu Lab · Understanding sheet · Kimba Christian