Skip to main content

Wave nature of Electromagnetic Radiations

 Wave nature of Electromagnetic Radiations


Maxwell , in 1873 , showed theoretically that an oscillating electrical circuit should radiate electromagnetic waves propagating with the velocity of light. 


The main features of this theory are :

1. Energy may be emitted from any source such as heated rod or filament of a bulb through which electric current is passed. Energy is emitted continuously in the form of radiations (waves). 

2. These waves are associated with oscillating electric field and magnetic field. These two fields are perpendicular to each other and perpendicular to the direction of propagation of the radiation as shown in the figure. 


Fig: Oscillating electric and magnetic fields emitted by charged particles. 


3. The radiations possess wave nature. Their velocity is equal to the velocity of light, i.e, 3×10⁸ m/sec. The radiations are called electromagnetic radiations or electromagnetic waves. 

4. Electromagnetic waves do not require any material medium for propagation. This rays of sun reach us through space. Space does not have material medium. But sound waves require medium and can not move in vacuum. 


Summary:

This suggested that light consisted of electromagnetic waves of extremely short wavelength. Fifteen years later, Hertz succeeded in producing short -wavelength waves of electromagnetic origin and showed that they possessed all the properties of light waves, such as reflection, refraction, polarization, etc. Thus Maxwell's electromagnetic theory of light was experimentally justified. 


Limitations of Electromagnetic Wave Theory

Electromagnetic wave theory explains the properties of light such as interference and diffraction etc. But this theory could not explain the following facts :

1. The phenomenon of black body radiation. 

2. The line spectra of atoms with special reference to hydrogen. 

3. The photoelectric effect. 

4. Variation of heat capacity of solids as a function of temperature. 


Labels:

Comments

Post a Comment

Please do not enter any spam link in the comment box.

Popular posts from this blog

Wave-Particle Duality

    Wave-Particle Duality One of the major phenomenon that can't be explained by classical mechanics is the wave-particle duality. Light waves act like particles and particles act like waves.           Fig: Wave-Particle duality Particle nature of light explains photoelectric effect and black body radiation. Wave nature of light explains the phenomenon of interference and diffraction.  Wave-particle duality is the ability of a matter to behave as a wave or particle.  The Schrodinger equation  determines the allowed wave functions for the system and how they evolve over time. A wave function behaves qualitatively like other waves such as water waves and waves on a string, because the Schrodinger equation is mathematically a type of wave equation. This explains the name 'wave function'  and gives rise to the wave -particle duality.  The wave of the wave function is not a wave in physical state, it is a wave in an abstract mathematical "space"  and in this respect
Post a Comment
Read more

Revolutionary attempts to solve the troubles of the periodic table

 Introduction The periodic table of the elements is one of the most powerful icons in science ; a single document that consolidates much of our knowledge of chemistry.For over a century, millions of children have started out every year on their journey into the fascinating world of chemistry with the periodic table of the chemical elements. Hundreds of versions of the periodic table have been proposed, and a variety of methods have been applied to its analysis.Throughout its long history, the periodic table has been disputed, altered and improved as science has progressed and as new elements have been discovered. But despite the dramatic changes, no revolution in the basic nature of the periodic system. After evolving for over 200 years through the work of many people, the periodic table remains at the heart of the study of chemistry  It ranks as one of the most fruitful ideas in the modern science. Efforts of many physicists and chemists  The modifications to quantum theory made by We
Post a Comment
Read more