Course name Engineering Physics Course Code BPHY101L Instructor Deepak Bhat slower c and larger atom faster Classical Mechanics Relativistic Mechanics smaller Quantum Mechanics Quantum Field Theory Assessment CAT Continuous Assessment Test FAT Final Assessment Test DAY 1 CAT 1 open notebook CAT 2 FAT Assignment 7th September Quiz Quiz Assessment CAT Continuous Assessment Test FAT Final Assessment Test DAY 1 CAT 1 open notebook CAT 2 FAT Assignment Quiz Quiz Relative weight CAT 1 CAT 2 30 FAT Assignments Quiz 40 30 Ass 1 Module 1 Introduction to waves Module 2 Electromagnetic waves CAT 1 Ass 2 Module 3 Elements of quantum mechanics Module 4 Applications of quantum mechanics CAT 2 FAT Module 5 Lasers Quiz Module 6 Propagation of EM waves in optical fibers Module 7 Opto electronic devices 1 Don t come late to the classes 2 Don t miss any classes 3 Take Notes come prepared for the class 4 Reading materials 5 Make a whatsapp group Module 1 Introduction to waves Ripples Sound waves E b B time t Electromagnetic waves Classification of waves 1 Mechanical vs Non mechanical 2 Transverse vs Longitudinal 2 Based on the dimension 1D 2D and 3D waves Module 1 Introduction to waves Ripples Sound waves E b B time t Electromagnetic waves Classification of waves 1 Mechanical Non mechanical Matter waves 2 Transverse vs Longitudinal 2 Based on the dimension 1D 2D and 3D waves Mechanical Waves Sound and water waves are mechanical waves meaning they require a medium to travel through Non mechanical Waves Electromagnetic wave is an example of non mechanical wave In vacuum electromagnetic waves move with speed of 3 x 108 ms 1 Matter waves Wave is associated with each moving particle which is called matter waves In quantum mechanics the wave nature of matter is also called dual nature De Broglie s hypothesis and Heisenberg uncertainty principle describes some of the properties of these waves Transverse waves In a transverse wave the wave direction is perpendicular the the direction that the string oscillates in Longitudinal waves in which the Waves medium particles is in the same direction in which the wave is propagating the motion of Mixed waves Surface waves In a surface wave particles of the medium move up and down as well as back and forth This gives them an overall circular motion These kind of waves can be called as mixed waves Seismic waves Love waves Transverse and Rayleigh waves longitudinal Waves at the surface of water 1D wave 2D wave 3D wave the The simplest wave is spatially one dimensional the waves These are one propagating dimension Example is the waves on a string in the waves These are in two propagating dimensions Example is the waves on the surface of water the waves These are in three propagating dimensions Example is the sound wave What is a wave Any disturbance propagating in medium can be called as a wave Wave Disturbance propagating in a medium disturbance time 0 v x v t 1 1 x disturbance time t 1 x 1 x A wave disturbance can be represented mathematically as f x vt or f x vt where x is the position of the disturbance at any time t v is the velocity of the wave Waves on a string A string without disturbance A string with periodic disturbance wave source Wave on a string Frequency is determined by the oscillation frequency of the source But wavelength depends on the properties of the medium Therefore velocity is also depends on the properties of the medium Let us derive the expression for wave velocity for waves on a string wave equation Engineering Physics Notes Deepak Bhat Module 1 Introduction to waves Waves A wave can be described as a disturbance that originates at a source and travels through a medium from one location to another Waves can be seen everywhere Ripples formed on the surface of the water sounds that we hear and light we see around us are common examples Water waves When you throw a rock into a pond the rock pushes water out of the way making a ripple that moves away from where it landed As the rock falls deeper into the river the water near the surface rushes back to ll in the space it left behind If there are no boundaries nearby the disturbance propagates on the surface of the water radially Sound waves Sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas liquid or solid Only those waves with frequencies lying between about 20 Hz and 20 kHz are audible to human beings Frequencies higher than the upper audible limit of human hearing 20 kHz are called ultrasound Sound waves below 20 Hz are known as infrasound Di erent animal species have varying hearing ranges At 20oC the speed of sound in air is about 343 meters per second Electromagnetic waves Electromagnetic wave is a special type of wave that does not require any medium for its prop agation The motion of electric charges generates an electromagnetic wave Radio waves microwaves infrared light visible light we have around us x rays and gamma rays all of these are examples of electromagnetic waves We will study them more in detail in the next module Classi cation of waves Mechanical non mechanical Electromagnetic and matter waves There are three types of waves based on whether the wave requires a medium for its propagation or not i mechanical waves and ii non mechanical waves Electro magnetic waves and iii Matter waves The waves that require a mechanical medium for their propagation are called mechanical waves or elastic waves In such waves the disturbance propagation depends on the elastic properties of the medium Examples of mechanical waves are ripples on the surface of the water sound waves spring waves seismic waves etc But not all waves require a mechanical medium For example electromagnetic waves do not require a mechanical medium for their propagation We will study the electromagnetic waves in more detail in the next module The third type of wave the wave that is associated with each moving particle which is called matter waves In quantum mechanics the wave nature of matter is also called dual nature De Broglie s hypothesis and Heisenberg uncertainty principle describes some of the properties of these waves These are special tye of waves Figure 1 Transverse and longitudinal waves Transverse longitudinal and mixed waves For mechanical waves there is another classi cation based on how the medium itself moves during wave propagation i Transverse waves ii longitudinal waves and iii mixed waves A transverse wave is a wave in which the medium moves
View Full Document
Unlocking...