35 multiple-choice questions in College Board exam style. Each has four choices and a full explanation of why each option is right or wrong.
Redraw the circuit before calculating. Identify which elements are truly in series vs. parallel: this is often the hardest and most important step.
Remember the mirror-image rule. Resistors add in series, combine reciprocally in parallel. Capacitors do the opposite.
For capacitor branches, check the timing. "Immediately after closing the switch" means treat an uncharged capacitor as a wire. "After a long time" means treat a charged capacitor as an open circuit.
Read the explanations even when you got it right. Each one teaches a small fact that often returns in a different form on the exam.