Circuits basics: Ohm’s law and power

What you’ll practice

Build fluency with Ohm’s law (V = IR) and power relationships (P = VI, P = I²R, P = V²/R) across common circuit situations. You’ll also get repetition on unit handling so your answers stay consistent.

Each question uses 4 options and there’s no timer, so you can pause to calculate carefully or review your reasoning.

Difficulty and quiz setup

Difficulty is mixed: straightforward plug-in questions appear alongside multi-step items that combine Ohm’s law with power and energy ideas. You can choose the question count and difficulty before starting to make it a quick warm-up or a full practice session.

• Convert confidently between volts, amps, ohms, watts, and kilowatt-hours
• Decide which formula fits the given information instead of guessing
• Interpret what changes when resistance, voltage, or current is increased
• Estimate results to catch impossible values before selecting an option
• Practice rearranging equations without algebra mistakes

Common pitfalls to avoid

Many misses come from unit slips (mA vs A, kΩ vs Ω) or mixing up power and energy. Another frequent trap is applying series/parallel intuition incorrectly when the question only targets a single component’s V, I, or R.

Tips for higher accuracy

Write down what’s given and what’s asked, then pick the simplest matching equation. If your result seems extreme, do a quick sanity check: doubling current should quadruple power in P = I²R, while doubling voltage quadruples power in P = V²/R.