Fresnel's Biprism Explained | Fringe Width, Virtual Sources & Wavelength (Interference Part 3)

#FresnelBiprism #InterferenceOfLight #EngineeringPhysics Fresnel's biprism explained step by step, with the reasoning behind every formula. This is Part 3 of the Interference of Light series. If you haven't seen the earlier parts, watch them first: Part 1 (add link) and Part 2, Young's Double Slit (add link). What you'll learn in this video: • History and importance of Fresnel's biprism • Construction of the biprism and why its refracting angle is very small • Experimental arrangement on the optical bench • How two virtual coherent sources are formed by refraction • Separation of the virtual sources, d = 2a(μ - 1)α • Fringe width and what it depends on • Overlap region and number of fringes • Determining the wavelength of light • Displacement method for finding d • Finding the thickness or refractive index of a thin sheet • Biprism experiment in white light • Effect of changing wavelength, screen distance, and biprism position • Comparison with Young's double slit experiment • Why / why-not reasoning for each concept Who is this for? Class 12 (Physics) and B.Tech first-year students studying Engineering Physics. Timestamps: 00:00 Introduction (add the rest after you check the video) Next video: Part 4, Interference in Thin Films (link coming soon) Concept Toh Clear Hai covers the syllabus chapter by chapter, with every topic explained clearly. Subscribe so you don't miss the next part. Note: This video was made with AI tools. For exams, always follow your own syllabus and textbook.