RMS Values for Different Waveforms | AC Graph Method | A2 Level | Alternating Current Lecture 5 скачать в хорошем качестве

RMS Values for Different Waveforms | AC Graph Method | A2 Level | Alternating Current Lecture 5

#alevelsphysics #education #physics #9702 #physics2026 In order to get the full crash course for A Level Physics Capacitance, please visit https://sirmahadamer.com/courses WhatsApp : https://wa.me/message/CKEDMPETUF4KA1 Instagram:   / mahad__amer   Notes: https://sirmahadamer.com/notes/altern... In Lecture 5 of the Alternating Current chapter for Cambridge A2 Level Physics (9702), the instructor explains how to calculate RMS (Root Mean Square) values for different types of waveforms, including non-sinusoidal currents such as square waves and irregular graphs. This lecture completes the Alternating Current (AC) chapter and focuses on exam-style problem solving using graphical methods. The equation only applies to pure sinusoidal waves. For other waveforms, RMS must be calculated using a more general method based on squaring, averaging, and square rooting the current values. The instructor demonstrates the step-by-step method to determine RMS values from a current–time graph: 1️⃣ Square the instantaneous current values on the waveform. 2️⃣ Find the total area under the squared graph over one full time period. 3️⃣ Divide the area by the total time to calculate the average squared value. 4️⃣ Take the square root of the result to obtain the RMS current. Using this method, the lecture solves several examples involving piecewise current graphs, demonstrating how the area under squared sections can be calculated and averaged to determine the RMS value. The lecture then explores square wave currents, where the waveform maintains a constant magnitude but alternates between positive and negative values. Because squaring removes the sign and the magnitude remains constant, the RMS value for a square wave is equal to its peak value. Another example involves unequal positive and negative current values, where the squared values are averaged over different time intervals to determine the RMS current. These examples help students understand how to apply the RMS concept to complex waveforms commonly seen in exam questions. The lecture concludes the Alternating Current chapter and prepares students to move on to the next topic: Magnetic Fields, after a short break before the midterm examinations. 📌 Topics Covered: • RMS value calculation for non-sinusoidal waveforms • Graphical method for RMS calculation • Squaring and averaging current–time graphs • RMS values for sinusoidal vs square wave currents • Angular frequency 𝜔 = 2𝜋𝑓 • AC voltage equation 𝑉 = 𝑉0 sin (𝜔𝑡) • Calculating resistance from RMS voltage and power • Exam-style problems on AC waveforms 🎯 Exam Focus: • Steps to calculate RMS from graphs • Difference between sinusoidal and square wave RMS values • Applying 𝑃 = 𝑉RMS/2 • Understanding angular frequency and AC voltage expressions