Alternating Current, Voltage & Terminologies| ALTERNATING CURRENT Physics 12 | Ch 20 | NBF | FBISE

Alternating Current, Voltage & Terminologies| ALTERNATING CURRENT Physics 12 | Ch 20 | National Book Foundation | Federal board #FederalBoard #ModelTownHumak #EducationalChannel #siranjumteaches #nationalbookfoundation In this lecture, we explore *Sinusoidal Alternating Current and Voltage* in detail, as per the **FBISE & Punjab Board Physics Class 12 curriculum (NBF Book)**. This topic is essential to understand how AC systems function in real-world applications, such as electricity supply and AC generators. 🔹 *Sinusoidal Alternating Current / Voltage:* An AC generator produces the current or voltage of the form: x = x₀ sin(ωt) Here, x is the instantaneous value of current or voltage. x₀ is the *peak (maximum)* value. ω is the **angular frequency**. For current: I = I₀ sin(ωt) For voltage: V = V₀ sin(ωt) The waveform is a **sine wave**, generated by rotating a coil in a magnetic field. This waveform: ✔ Changes polarity regularly ✔ Varies smoothly in magnitude ✔ Crosses zero rapidly and peaks slowly 🔹 *AC Terminologies Explained:* *Cycle:* One complete waveform of positive and negative values *Time Period (T):* Time for one full cycle *Frequency (f):* Number of cycles per second (Hertz) *Average Value:* Not used in power calculations for sine waves, since average over one cycle is zero *Peak Value (x₀):* The highest positive/negative value in a cycle *Root Mean Square (RMS) Value:* Equivalent DC value producing same heat: I_rms = I₀ / √2 V_rms = V₀ / √2 RMS value is used in practical power ratings. 🔹 *Power in AC Circuits:* Mean (average) power in a resistive load is: P = (1/2) I₀² R This shows that average power is *half* of maximum power in purely resistive AC circuits. 📚 This video is ideal for: Class 12 Physics students (FSc Part 2) Students of FBISE / Punjab Boards MDCAT & ECAT aspirants Anyone needing conceptual clarity on *AC physics* 🎥 Don't forget to like, share, and subscribe for more Physics lessons with Sir Anjum. #AlternatingCurrent #Physics12 #FScPhysics #SinusoidalVoltage #VoltageAndCurrent #RMSValue #PeakValue #PhysicsLecture #FBISE #NBFPhysics #Class12Physics #ACWaveform #RootMeanSquare #PowerInAC #FScChapter20 #AlternatingVoltage #FScBoardExam #PhysicsChapter20 #PhysicsWithGraphs #NBFClass12Physics #FScPart2