CLASS 12 PHYSICS | NCERT Ch 7: ALTERNATING CURRENT — Very Basics-1 | Mean & RMS Value

In this session, we cover the Mean (Average) Value of AC, RMS Value of AC, and the Form Factor in detail. The lecture explains key properties of alternating current, important formulas, their physical significance, and includes solved examples to strengthen your understanding. We also practice Assertion-Reason type questions and tricky interval-based average problems, making this video highly useful for CBSE Class 12 Physics, JEE, NEET, CUET, and other competitive exams. ⏱ Timestamps 00:00 — Intro 01:26 — Mean (Average) Value of AC (Concept + Formula) 04:22 — RMS Value & Form Factor (Concept + Application) 06:49 — Example 1: i = 5 sin(300t – φ) → Peak, RMS, Frequency, Average 12:07 — Example 2: Graph-based Average Value (interval method explained) 19:02 — Assertion-Reason Practice Question (with tips) 21:45 — Example 3 (MCQ): i = 5 + 5 sin(100t) → Average over one cycle 🔑 Key Concepts (Quick Revision) Mean (Average) Value of AC (half cycle): Constant current that sends the same charge in half-cycle as AC. RMS (Root Mean Square) Value: Constant current producing same heating effect as AC in one cycle. Form Factor: Ratio = RMS value ÷ Average value (commonly used for rectified waves). Standard sinusoidal relations (i = I₀ sin ωt): Peak value = I₀ RMS value = I₀ / √2 Average over full cycle = 0 Average over half cycle = (2/π) I₀ Angular frequency: ω = 2πf → f = ω / (2π) 📘 Worked Examples 1️⃣ For i = 5 sin(300t − φ): Peak current (I₀), RMS current, Frequency, Average value 2️⃣ Graph-based average calculation over intervals: (i) t/2 to t (ii) t/4 to 3t/4 3️⃣ Complex wave: i = (5 + 5 sin 100t) A → Find average over one cycle Options: (i) 10 A (ii) 5 A (iii) √50 A (iv) 0 A 0:00 Intro 1:26 Mean (Average) value of AC 4:22 RMS value & Form Factor 6:49 Example 1 — sinusoid numerical 12:07 Graph problem — method 19:02 Assertion-Reason tips 21:45 Example 3 — complex wave (MCQ) Mean and RMS values of AC explained with solved examples — perfect for Class 12 & competitive exam prep. Visit sethiswiftlearn.com NEET 2025 Physics Paper Solution 👉 https://sethiswiftlearn.com/neet-2025... JEE-MAIN 2025 Maths Paper Solution 👉 https://sethiswiftlearn.com/jee-main-... 📌 Playlists 🔹 Class 11 Physics Playlist    • Learn Vernier Calipers in Minutes | Class ...   🔹 Class 12 Physics Playlist    • CURRENT ELECTRICITY – Very Basics-2 | Clas...   🔹 Class 11 Maths Playlist    • Class 11 Physics (+1 Physics)   🔹 Class 12 Maths Playlist    • Class 12 Maths (+2 Maths)   #Class12Physics #AlternatingCurrent #NCERT #JEE #NEET #CUET #PhysicsLecture