AC through a Resistor

Voltage and current are in phase.

Concept

AC through a Resistor is a foundational idea in this chapter. The defining relationship is:

$I = V_0\sin(\omega t)/R$

Power: P = V_rms I_rms = V_rms²/R.

Worked Application

Apply the formula to a typical problem from your textbook. Identify the knowns, plug into the equation, and check that the units work out. Always sanity-check the magnitude before accepting an answer.

Common Confusions

• Confusing the variables in the formula — re-read the symbol definitions in the chapter.
• Forgetting unit conversions (cm vs m, g vs kg).
• Ignoring sign conventions where direction matters.

Key Takeaways

• Master the formula $I = V_0\sin(\omega t)/R$ and one canonical example.
• See the chapter index for full derivations, traps and exam-grade problems.