COMPTON'S EFFECT | Physics 12 | Ch 21 QUANTUM PHYSICS | FBISE | NBF | Lec 3

COMPTON'S EFFECT | Physics 12 | Ch 21 QUANTUM PHYSICS | Lecture 3 | National Book Foundation | Federal Board #FederalBoard #ModelTownHumak #EducationalChannel #siranjumteaches #nationalbookfoundation In this lecture of *Chapter 21: Quantum Physics (Physics 12, FBISE, National Book Foundation)* we study **Compton’s Effect**, discovered by Arthur H. Compton in 1923. 👉 *Key Concepts Covered:* *Definition:* Compton’s Effect is the increase in wavelength (Compton shift) of X-rays or gamma rays after scattering from electrons. *Experiment:* A beam of X-rays with wavelength λ is directed at graphite. Scattered X-rays show longer wavelength λ’, proving photon–electron interaction. *Photon as Particle:* Compton explained that photons behave like particles. When a photon collides with an electron at rest, it transfers **energy & momentum**, similar to billiard balls. *Energy Conservation:* hf = K.E + hf’ *Momentum Conservation:* p = p₀ + p’ *Photon Momentum:* p = h/λ *Compton’s Equation:* Δλ = (h/mc)(1 – cosθ) *Compton Wavelength:* h/mc = 0.00243 nm, a constant. *Key Point:* The shift Δλ depends only on scattering angle θ, not on the wavelength of incident photons or the material. 👉 *Importance:* Compton’s experiment confirmed the **particle nature of light**, supported **Einstein’s photon theory**, and became a cornerstone of **Quantum Physics**. This lecture explains *Compton’s experiment, equations, photon momentum, conservation laws, and significance* for Class 12 Physics students preparing for board exams. Hashtags: #ComptonsEffect #QuantumPhysics #Physics12 #ModernPhysics #FBISE #NationalBookFoundation #PhotonTheory #Xrays #Class12Physics #BoardExamPreparation #SirAnjumTeaches Compton Effect Physics 12, Compton Shift Quantum Physics, Arthur Compton Experiment Physics, Photon momentum Physics 12, Compton Wavelength 0.00243 nm, Conservation of Energy and Momentum Compton Effect, Particle nature of light Physics 12, X-ray scattering Compton Effect, Quantum Physics Class 12 Lecture, National Book Foundation Physics 12, FBISE Physics Quantum Chapter, Applications of Compton Effect, Einstein Photon Theory and Compton Effect, Class 12 Physics Board Preparation, Sir Anjum Teaches Lec 3