Alternating Current
12th Class Physics Chapter 20 Notes FBISE
Explore AC waveforms, RMS voltage, mean power, diode rectification, filter circuits, self/mutual induction, phase lags/leads across R-L-C components, and RL/RC series impedance.
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Quick Answer
Comprehensive 12th Class Physics Chapter 20 Alternating Current (AC) notes for Federal Board (FBISE) HSSC-II students. This page covers AC terminologies, peak and RMS values, mean/maximum power factor, half-wave and full-wave rectification with capacitive filtering, self and mutual inductance, phase relationships in pure R, L, and C elements, and phasor vector impedance derivations for RL and RC series AC circuits following the NBF 2026-2027 curriculum.
Chapter Overview
Chapter 20 Alternating Current analyzes time-varying electrical signals and AC circuit theory. Students examine sinusoidal voltage and current waveforms, deriving mathematical relationships for peak values, root mean square (RMS) values, and average/maximum power dissipation.
The chapter details semiconductor diode rectification, comparing half-wave and full-wave bridge rectifier circuits, and explaining smoothing filter capacitors. It investigates electromagnetic induction principles, including self-inductance L, mutual inductance M, and magnetic energy storage.
Finally, the course analyzes phase relationships across pure resistors, inductors, and capacitors. It derives phasor diagrams and impedance Z equations for RL and RC series AC circuits. Solved exercise questions and numericals are included for full board preparation.
Chapter 20 Notes Material
Use the following study material to prepare Chapter 20 completely.
Download Chapter 20 PDF
Download the free PDF notes for 12th Class Physics Chapter 20 Alternating Current. Study offline with high-quality solved exercises, AC phasor derivations, rectification diagrams, and objective MCQs formatted for FBISE exams.