Charging & Discharging of a Capacitor| Electric Potential & Capacitor| Ch 19 | Physics 12 | NBF

Charging & Discharging of a Capacitor| Electric Potential & Capacitor| Physics 12 | National Book Foundation | Federal Board #FederalBoard #ModelTownHumak #EducationalChannel #siranjumteaches #nationalbookfoundation 📘 In this lecture, we cover the important topic *"Charging and Discharging of a Capacitor"* from Chapter: Electric Potential and Capacitor, Physics Class 12 (NBF) for FBISE students. 🔋 When a capacitor is connected in an RC (Resistor-Capacitor) circuit: • The *charging process* begins with maximum current and zero voltage across the capacitor. • As time passes, voltage rises exponentially while current decreases. • The *maximum charge* a capacitor holds is given by: Q₀ = C × emf. • Charging follows the exponential law: Q = Q₀(1 - e^(-t/RC)) 🧾 **Time Constant (τ = RC)**: • After time t = RC, the capacitor charges up to *63.2%* of its maximum. • This time constant defines the rate of both charging and discharging. ⚡ In **discharging**, the capacitor releases its stored energy through the resistor: • Discharge current starts high and gradually drops to zero. • Discharge formula: Q = Q₀ e^(-t/RC) • After t = RC, the charge drops to *36.7%* of its initial value. 📊 Graphs for both charging and discharging are explained and interpreted. 🔁 These exponential relationships also apply to voltage and current during the capacitor's charge/discharge cycle. 🎯 This topic is essential for: • Conceptual understanding of capacitors in circuits • Federal Board exam preparation • Competitive entry tests 📚 Book: Physics Class 12 – National Book Foundation 📘 Board: FBISE (Federal Board of Intermediate & Secondary Education) 📍 Lecture 7 | Chapter: Electric Potential & Capacitor 👨‍🏫 Instructor: Sir Anjum Teaches 👍 Like | 💬 Comment | 📢 Share | 📚 Subscribe for more lectures #ChargingCapacitor #DischargingCapacitor #RCcircuit #Physics12 #Class12Physics #FederalBoard #CapacitorPhysics #CapacitorCharging #CapacitorDischarging #SirAnjumTeaches #NBFPhysics #FBISEPhysics