Physics  >  Modern Physics for IIT JAM  >  Introduction: Quantum Physics

Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics

Document Description: Introduction: Quantum Physics for Physics 2022 is part of Modern Physics for IIT JAM preparation. The notes and questions for Introduction: Quantum Physics have been prepared according to the Physics exam syllabus. Information about Introduction: Quantum Physics covers topics like and Introduction: Quantum Physics Example, for Physics 2022 Exam. Find important definitions, questions, notes, meanings, examples, exercises and tests below for Introduction: Quantum Physics.

Introduction of Introduction: Quantum Physics in English is available as part of our Modern Physics for IIT JAM for Physics & Introduction: Quantum Physics in Hindi for Modern Physics for IIT JAM course. Download more important topics related with notes, lectures and mock test series for Physics Exam by signing up for free. Physics: Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics
1 Crore+ students have signed up on EduRev. Have you?

Introduction: Quantum Physics

  • Quantum mechanics, science dealing with the behaviour of matter and light on the atomic and subatomic scale. It attempts to describe and account for the properties of molecules and atoms and their constituents—electrons, protons, neutrons, and other more esoteric particles such as quarks and gluons. These properties include the interactions of the particles with one another and with electromagnetic radiation (i.e., light, X-rays, and gamma rays).
    Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics
  • The behaviour of matter and radiation on the atomic scale often seems peculiar, and the consequences of quantum theory are accordingly difficult to understand and to believe. Its concepts frequently conflict with common-sense notions derived from observations of the everyday world. 
  • There is no reason, however, why the behaviour of the atomic world should conform to that of the familiar, large-scale world. It is important to realize that quantum mechanics is a branch of physics and that the business of physics is to describe and account for the way the world—on both the large and the small scale—actually is and not how one imagines it or would like it to be.
  • The study of quantum mechanics is rewarding for several reasons. First, it illustrates the essential methodology of physics. Second, it has been enormously successful in giving correct results in practically every situation to which it has been applied. There is, however, an intriguing paradox.
  • In spite of the overwhelming practical success of quantum mechanics, the foundations of the subject contain unresolved problems—in particular, problems concerning the nature of measurement. An essential feature of quantum mechanics is that it is generally impossible, even in principle, to measure a system without disturbing it; the detailed nature of this disturbance and the exact point at which it occurs are obscure and controversial. 
  • Thus, quantum mechanics attracted some of the ablest scientists of the 20th century, and they erected what is perhaps the finest intellectual edifice of the period.

History of developments in Quantum Mechanics 

  • The history of quantum mechanics began primarily with Michael Faraday's discovery of cathode rays in 1838 and Gustav Kirchhoff's formulation of the black body radiation problem in the winter of 1859–1860.
  • Max Planck's 1900 quantum hypothesis proved a stepping stone in the quantum mechanics. It states that that any energy-radiating atomic system can theoretically be divided into a number of discrete ‘energy elements’ ε such that each of these energy elements is proportional to the frequency v with which they each individually radiate energy, as defined by the following formula: 
                                                E = hν, where h is referred to as Planck's constant
    Question for Introduction: Quantum Physics
    Try yourself:Green light has a wavelength of 525 nm. Determine the energy for the green light in joules.
    View Solution
  • Then, in 1905, Albert Einstein proposed, based on Planck's quantum hypothesis, that light itself is made up of individual quantum particles, which later came to be known as photons, to explain the photoelectric effect (1839), which states that shining light on certain materials can function to eject electrons from the material (1926). 
  • Max Born initially introduced the term "quantum mechanics" in his 1924 paper "Zur Quantenmechanik."
  • The further developments in quantum mechanics are represented on the timeline provided below.

Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics


Question for Introduction: Quantum Physics
Try yourself:What is the typical unit of measurement for 'E' in the following equation?

E = hv

View Solution

Some Examples

Q.1. What is the difference between classical and quantum mechanics? 
Ans. Classical mechanics describes the behavior of macroscopic bodies, which have relatively small velocities compared to the speed of light. Quantum mechanics describes the behavior of microscopic bodies such as subatomic particles, atoms, and other small bodies. 


Q.2. The Quantum Mechanical Model of the atom was proposed by:
Ans.
Erwin Schrödinger proposed the quantum mechanical model of the atom, which treats electrons as matter waves.

Q.3. The wavelength of the matter waves is independent of ______.
Ans. 
The wavelength of the matter wave is independent of charge.

The document Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics is a part of the Physics Course Modern Physics for IIT JAM.
All you need of Physics at this link: Physics
54 videos|44 docs|15 tests
Download as PDF

Download free EduRev App

Track your progress, build streaks, highlight & save important lessons and more!

Related Searches

practice quizzes

,

Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics

,

Previous Year Questions with Solutions

,

Summary

,

video lectures

,

Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics

,

Semester Notes

,

pdf

,

Viva Questions

,

Extra Questions

,

ppt

,

Exam

,

Introduction: Quantum Physics Notes | Study Modern Physics for IIT JAM - Physics

,

Sample Paper

,

Important questions

,

Objective type Questions

,

study material

,

mock tests for examination

,

Free

,

past year papers

,

MCQs

,

shortcuts and tricks

;