Title 02.Physical-World-Units-and-Measurements-F.pdf ✅

Physics Smart Booklet 1 Physics Smart Booklet Theory + NCERT MCQs + Topic Wise Practice MCQs + NEET PYQs 02.Physical World, Units and Measurements
Physics Smart Booklet 2
Physics Smart Booklet 3 PHYSICAL WORLD Physics  Physics deals with the study of the basic laws of nature and their manifestation in different phenomena. The basic laws of physics are universal and are applied in widely different contexts and conditions. Physics, Technology and Society  Science, Technology and Society have strong relationships among one on other. Science is the mother of technology and both of them are the reasons for the creation and development of the society.  Science and technology issues are actually discussed worldwide today. Progress in this has led to produce the ability to integrate different types of physical products.  Physics is a basic discipline in the category of natural sciences which also includes other disciplines like Chemistry and Biology. The word physics comes from a Greek word meaning nature. Fundamental forces in nature :  There are four fundamental forces in nature. They are the ‘gravitational force’, the ‘electromagnetic force’, the ‘strong nuclear force’, and the ‘weak nuclear force’. Unification of different forces/domains in nature is a basic quest in physics. Nature of physical laws :  (i) The physical quantities that remain unchanged in a process are called conserved quantities. Some of the general conservation laws in nature include the laws of conservation of mass, energy, linear momentum, angular momentum, charge, etc. Some conservation laws are true for one fundamental force but not for the other. (ii) Conservation laws have a deep connection with symmetries of nature. Symmetries of space and time, and other types of symmetries play a central role in modern theories of fundamental forces in nature. 1.Some physicists from different countries of the world and their major contributions Name Major contribution /Discovery Country of Origin Archimedes Principle of buoyancy; Principle of the lever Greece Galileo Galilei Law of inertia Italy Christiaan Huygens Wave theory of light Holland Isaac Newton Universal law of gravitation ; Laws of motion ; Reflecting telescope U.K. Michael Faraday Laws of electromagnetic induction U.K. James Clerk Maxwell Electromagnetic theory; Light - an electromagnetic wave U.K. Heinrich Rudolf Hertz Generation of electromagnetic waves Germany J.C. Bose Short radio waves India W.K.Roentgen X-rays Germany J.J. Thomson Electron U.K. Marie sklodowska Curie Discovery of radium and polonium; Studies on natural radio activity poland Albert Einstein Explanation of photoelectric effect;Theory of relativity Germany Victor Francis Hess Cosmic radiation Austria R.A. Millikan Measurement of electronic charge U.S.A. Ernest Rutherford Nuclear model of atom New Zealand Niels Bohr Quantum model of hydrogen atom Denmark C.V. Raman Inelastic scattering of light by molecules India Louis Victor de Broglie Wave nature of matter France M.N. Saha Thermal ionisation India S.N. Bose Quantum statistics India
Physics Smart Booklet 4 Wolfgang Pauli Exclusion principle Austria Enrico Fermi Controlled nuclear fission Italy Werner Heisenberg Quantum mechanics; Uncertainity principle Germany Paul Dirac Relativistic theory of electron; Quantum statistics U.K. Edwin Hubble Expanding universe U.S.A. Ernest Orlando Lawrence Cyclotron U.S.A. James Chadwick Neutron U.K. Hideki Yukawa Theory of nuclear forces Japan Homi Jehangir Bhabha Cascade process of cosmic radiation India Lev Davidovich Landau Theory of condensed matter; Liquid helium Russia S.Chandrasekhar Chandrasekhar limit, structure and evolution of stars India John Bardeen Transistors ; Theory of super conductivity U.S.A. C.H. Townes Maser; Laser U.S.A. Abdus Salam Unification of weak and electromagnetic interactions Pakistan 2) Link between technology and physics Technology Scientific principle (s) Steam engine Laws of thermodynamics Nuclear reactor Controlled nuclear fission Radio and Television Generation, propagation and detection of electromagnetic waves Computers Digital logic Lasers Light amplification by stimulated emission of radiation Production of ultra high Superconductivity magnetic fields Rocket propulsion Newton’s laws of motion Electric generator Faraday’s laws of electromagnetic induction Hydroelectric power Conversion of gravitational potential energy into electrical energy Aeroplane Bernoulli’s principle in fluid dynamics Particle accelerators Motion of charged particles in electromagnetic fields Sonar Reflection of ultrasonic waves Optical fibres Total internal reflection of light Non-reflecting coatings Thin film optical interference Electron microscope Wave nature of electrons Photocell Photoelectric effect Fusion test reactor (Tokamak) Magnetic confinement of plasma Giant Metrewave Radio Detection of cosmic radio waves Telescope ( GMRT) Bose-Einstein condensate Trapping and cooling of atoms by laser beams and magnetic fields Units and Measurements 2.1 Units Fundamental quantities The physical quantities which are independent of other quantities are called fundamental quantities. Example: Mass, length, time etc. Quantities are those which can be measured using an instrument. Any physical phenomenon or observation that can be measured using an instrument is called quantity. Derived quantities The physical quantities which are derived from fundamental quantities are known as derived quantities. Example: Density, volume, speed, force etc.