2nd Year Physics Chapter 19 Notes

• NAVSTAR navigation system
• Black body radiation, Intensity distribution diagram plans assumption the phone Photon
• Interaction of electromagnetic radiation with matters
• (i) Photoelectric effect  (ii) Compton effect  (iii) Pair production
• Important 2nd year physics chapter 19 numericals for Intermediate part-II students.
• Explanation on the basis of Quantum theory
• Annihilation of matter 
• Wave nature of particle
• Davisson and Germer experiment
• Important 2nd year physics chapter 19 notes pdf for Intermediate part-II students.
• Wave-Particle duality
• Uses of wave nature of particles
• Electron microscope
• Uncertainty Principle
• Important 2nd year physics chapter 19 important questions for Intermediate part-II students.
• 1. Distinguish between inertial and non-mertial frames of references.
• 2. Describe the postulates of special theory of relativity and its results.
• 3. Understand the NAVASTAR navigation system.
• 4 Understand the concept of black body radiation.
• Important 2nd year physics chapter 19 conceptual questions for Intermediate part-II students.
• 5. Understand and describe how energy is distributed over the wavelength range for several values of source temperature.
• 6. Know Planck’s assumptions.
• 7. Know the origin of quantum theory.
• Important 2nd year physics chapter 19 conceptual questions for Intermediate part-II students.
• 8. Show an appreciation of the particle nature of electromagnetic radiation.
• 9. Describe the phenomenon of photoelectric effect.
• 10. Explain photoelectric effect in terms of photon energy and work function.
• 11. Explain the function of photocell and describe its uses.
• Important 2nd year physics chapter 19 long questions for Intermediate part-II students.
• 12. Describe Compton's effect.
• 13. Explain the phenomena of pair production and pair annihilation.
• 14 Describe de-Broglie’s hypothesis of wave nature of particles
• Important 2nd year physics chapter 19 exercise short questions for Intermediate part-II students.
• 15. Describe and interpret qualitatively the evidence provided by electron diffraction for the wave nature of particles.
• 16. Understand the working principle of electron microscope
• 17. Understand and describe uncertainty principle.
• Important 2nd year physics chapter 19 solved exercise for Intermediate part-II students.
• In the early part of the twentieth century, many experimental and theoretical problems remained unresolved. Attempts to explain the behaviour of matter on the atomic level with the laws of classical physics were not successful. Phenomena such as black body radiation, the photoelectric effect, the emission of sharp spectral lines by atoms in a gas discharge tube, and invariance of speed of light, could not be understood within tho framework of classical physics. To explain these observations a revolutionary framework of explanation was necessary which we call modem physics. Its two most significant features are relativity and quantum theory. The observations on objects moving very fast, approaching the speed of light, are well explained by the special theory of relativity. Quantum theory has been able to explain the behaviour of electromagnetic radiation as discrete packets of energy and the particles on a very small scale are dominated by wave properties.
• Important 2nd year physics chapter 19 exercise for Intermediate part-II students.
• Classical physics is still valid in ordinary processes of everyday life. But to explain the behaviour of tiny or very fast moving particles, we have to use the above mentioned theories. In this chapter, we shall discuss Various aspects of theory of relativity and quantum theory. Before introducing special theory of relativity, some related terms are discussed briefly.
• Important 2nd year physics chapter 19 solved numericals for Intermediate part-II students.
• RELATIVE MOTION: When we say a ball is thrown up. the 'up' direction is only for that particular place. It will be 'down' position for a person on the diametrically opposite side of the globe. The concept of direction is purely relative. Similarly, the rest position or the motion of an object is not same for different observers. For example, the walls of the cabin of a moving train are stationary with respect to the passengers sitting inside it but are in motion to a person stationary on the ground. So we cannot say whether an object is absolutely at rest or absolutely in motion. All motions are relative to a person or instrument observing it.