[1] Photoelectric effect provides evidence that light behaves as particles called photons, with each photon having energy hν. This explains the threshold frequency and instantaneous emission.
[2] Compton scattering demonstrates that photons transfer discrete packets of energy and momentum to electrons during collisions, with the photon's wavelength increasing in accordance with conservation laws. This provided direct evidence that photons are real particles.
[3] Pair production demonstrates that a photon's energy can be converted into an electron-positron pair, as predicted by Einstein's equation E=mc2. A minimum photon energy of 1.02 MeV is required to produce the pairs.
origin of quantum physics -
Inadequacy of classical mechanics and birth of QUANTUM PHYSICS
ref: Quantum mechanics: concepts and applications, N. Zettili
Lecture slides from a class introducing quantum mechanics to non-majors, giving an overview of black-body radiation, the photoelectric effect, and the Bohr model. Used as part of a course titled "A Brief history of Timekeeping," as a lead-in to talking about atomic clocks
origin of quantum physics -
Inadequacy of classical mechanics and birth of QUANTUM PHYSICS
ref: Quantum mechanics: concepts and applications, N. Zettili
Lecture slides from a class introducing quantum mechanics to non-majors, giving an overview of black-body radiation, the photoelectric effect, and the Bohr model. Used as part of a course titled "A Brief history of Timekeeping," as a lead-in to talking about atomic clocks
i am student of M.Sc (Physics) in university of sindh. it is my first book on high energy physics and i will also upload the new version of this book soon. so please read this book and give me feed back on my email address.
Fundamentals of modern physics, the de-Broglie hypothesisPraveen Vaidya
The presentation uploaded here educates about the failure of classical physics to explain Blackbody radiation and the success of quantum theory to explain the Blackbody radiation spectrum and other phenomena, the de-Broglie hypothesis and its significance, nature of de-broglie waves and the representation. Numerical problems are given at the end.
i am student of M.Sc (Physics) in university of sindh. it is my first book on high energy physics and i will also upload the new version of this book soon. so please read this book and give me feed back on my email address.
Fundamentals of modern physics, the de-Broglie hypothesisPraveen Vaidya
The presentation uploaded here educates about the failure of classical physics to explain Blackbody radiation and the success of quantum theory to explain the Blackbody radiation spectrum and other phenomena, the de-Broglie hypothesis and its significance, nature of de-broglie waves and the representation. Numerical problems are given at the end.
Thomas Del Mar Ltd
In association with Sotherby's
ANTIQUE ARMS, ARMOUR & MILITARIA
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McGladrey Guide to Accounting for Business Combinations - Second EditionBrian Marshall
A Guide to Accounting for Business Combinations is designed to help assist growing, owner-managed and public companies in their application of Topic 805, "Business Combinations," of the FASB Accounting Standards Codification®. Topic 805 has been in effect since 2009, and the Guide addresses many insights gained as a result of the application of this guidance since its effective date.
The Earliest Codification of Hadith: Kitab al-Sard wa al-Fard
By Abu al-Khayr Ahmad bin Ismail al-Qazwini
The Book of Continuous Reports by Single Narrators Collected in Brochures, and copies thereof.
Includes the full Arabic Text.
The branch of science which considers the dual behavior of matter is called quantum mechanics. The quantum mechanics model of atom ia based on quantum mechanics.
60508_paticle like properties of waves.pptxClaireSadicon
Discussion of Properties of Waves
The particle-like properties of electromagnetic radiation
Classical Postulates
Einstein theory
Black Body Radiation
Stefan's radiation law
Wein's displacement law
Rayleigh-Jeans Formula
Planck’s Theory and Radiation Law
The Compton Effect
Bremsstrahlung and X-Ray Production
Pair production
Electron-Positron Annihilation
Thesis on the masses of photons with different wavelengths.pdf WilsonHidalgo8
It deals with the methods and calculations to measure the masses of photons with different wavelengths.
where I was able to create two experimental calculations to explain the measurements of the masses of the photons.
and I hope that this thesis competes with others, in order to obtain a physics prize.
Ohm's Law V = I x R (Volts = Current x Resistance). The Ohm (Ω) is a unit of electrical resistance equal to that of a conductor in which a current of one ampere is produced by a potential of one volt across its terminals. 1)Measurement of Low resistance: 1) Ammeter Voltmeter method: This is very popular method for measurement of medium resistances since ...
Ohm's Law V = I x R (Volts = Current x Resistance). The Ohm (Ω) is a unit of electrical resistance equal to that of a conductor in which a current of one ampere is produced by a potential of one volt across its terminals. 1)Measurement of Low resistance: 1) Ammeter Voltmeter method: This is very popular method for measurement of medium resistances since ...
The static characteristics are defined for the instruments which measure quantities which do not vary with time. ... The accuracy of a measurement indicates the nearness to the actual/true value of the quantity. 7. 2.Sensitivity Sensitivity is the ratio of change in output of an instrument to the change in input.
The inverse quantity is electrical conductance, and is the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with the notion of mechanical friction. The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S).
Explain about 3 Basic Types of Energy Meters? Watt hour meter or energy meter is an instrument which measures amount of electrical energy used by the consumers. ... Electromechanical induction type Energy meter.
The devise that is used for measurement of certain physical quantity is called as measuring instrument. This article discusses what the measuring instruments are, their types, functions of the measuring instruments and advantages and disadvantages of the analogue and digital ...
The Cathode Ray Oscilloscope is an instrument which we use in laboratory to display measure and analyze various waveforms of various electrical and electronic circuits. Actually cathode ray oscilloscope is very fast X-Y plotters that can display an input signal versus time or other signal.
Permanent Magnet Moving Coil Instrument. The permanent magnet moving coil instrument or PMMC type instrument uses two permanent magnets in order to create stationary magnetic field.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
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Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
2. Quantum Mechanics: (i) Particle properties of waves:
Black body radiation, photoelectric effect, x-ray
Diffraction and Compton effect, pair production, photon
and gravity.
References:
A. Beiser, Concept of Modern Physics (or Perspective of Modern
Physics), Tata-McGraw Hill, 2005
Course Outline...
3. ELECTROMAGNETIC SPECTRUM
Particle aspect of radiation
Classical physics: a particle : energy E and momentum p
Wave : an amplitude and wave vector k
4.3 x 1014 7.5 x 1014
4. Principle of superposition
A characteristic properties of all waves
Particle: e.g e-: charge, mass : laws of particle mechanics
General Consensus:
Waves: em waves: diffraction, interference, polarization etc
5. Young’s experiment: Light consists of waves
Black Body Radiation
Classical approach
Only the quantum theory of
light can explain its origin
An ideal “blackbody”, is a material object that absorbs all of the radiation
falling on it, and hence its appears as black under reflection when
illuminated from outside.
Black Body
When an object is heated , it radiates electromagnetic energy as a result of the
thermal agitation of the electrons in its surface
Blackbody radiation: radiation leaving the hole of a heated hollow cavity or
the radiation emitted by a blackbody when hot.
6. Classical: continuous energy distribution
EXPERIMENTAL
Radiation inside a cavity:
series of standing waves.
Density of standing
waves in cavity:
Classical average energy
per standing wave:
Rayleigh’s assumption: a standing wave can exchange any
amount(continum) of energy with matter,
Rayleigh & Jeans
2
2
8
)(
c
d
dG
kT
Rayleigh-Jeans formula:
d
c
kT
dGdu 2
2
8
)()(
7. Classical physics failure introduction of Q.M.
As increases toward the ultraviolet end of the spectrum, the energy density
should increase as 2. In the limit of infinitely high , u()d should also go to .
In really, of course, the energy density falls to 0 as . This discrepancy called
ultraviolet catastrophe.
Consequences:
Ultraviolet catastrophe
Planck’s formula
The energy exchange between radiation and matter must be
discrete and energy of radiation E = nh
1/
3
2
8
)(
kTh
e
d
c
h
du
1/
kTh
e
h
Average energy per standing wave
Planck’s modifications
h = 6.626 x 10-34 J.s
Max Planck (1918 Nobel prize)
8. SUMMARYAt low At high
d
c
kT
d
h
kT
c
h
du
2
3
3
2
8
8
)(
Rayleigh & Jeans
h >> kT
kTh
e /
0)( du
h << kT
hkT
kThe kTh
/
1/1
11
1/
# of modes per
unit frequency
per unit volume
Probability of
occupying modes
Average
energy per
mode
CLASSICAL
Equal for all modes kT
QUANTUM
Quantized modes:
require h energy to
excite upper modes,
less probable
3
2
8
c
3
2
8
c
1kT
h
e
h
9. Particle properties of waves:
[1] Photoelectric effect
[2] Compton effect
[3] Pair production
EXPERIMENTAL CONFIRMATION
10. Photoelectric effect
Provides a direct confirmation for
the energy quantization of light.
The phenomenon of ejection of electron from the surface of a metal when light
of a suitable frequency strikes on It, is called photoelectric effect. The emitted
electrons are called photo-electrons.
The time between the incidence
and emission of a photoelectron is
very small, 10–9 s.
V0
Heinrich Hertz in 1887
later on, it was explained by Albert Einstein in 1905
It was during this study of electromagnetic waves that he saw that if you send ultraviolet
light onto metals, you'll get sparks coming off
Experimental
Classical: raise intensity more electrons
independent of frequency
Observed: No electron below threshold frequency
11. The following experimental laws were discovered:
The kinetic energy of the ejected electrons depends on the
frequency but not on the intensity of the beam; the kinetic energy of
the ejected electron increases linearly with the incident frequency.
If the frequency of the incident radiation is smaller than the
metal’s threshold frequency(a frequency that depends on the
properties of metal), no electron can be emitted regardless of the
radiation’s intensity.
No matter how low the intensity of the incident radiation,
electrons will be ejected instantly the moment the frequency of the
radiation exceeds the threshold frequency.
At a fixed frequency, the number of ejected electrons increases
with the intensity of the light but doesn’t depend on its frequency.
12. Classical physics fails: for dependence of the
effect on the threshold frequency
K = h - W = h - h0
0 = threshold frequency
The stopping potential : at which all of
the electrons will be turned back before
reaching the collector
e
W
e
hc
e
W
e
h
VS
Work function: W = h0
Larger W needs more energy needed for an
electron to leave
Photoelectric effect:
metal
E = h0
KE = 0
KEmax
= h - h0
E = h
Einstein interpretation(1905)
Light comes in packets of energy (photons)
E = h
An electron absorbs a single photon to leave the material
0
K
13. When two UV beams of wavelengths 1 = 280nm and 2 = 490nm fall on a lead
surface, they produce photo electrons with maximum kinetic energies 8.7eV and
6.67eV, respectively. (a) calculate the value of planck constant. (b) Calculate the
work function and the cutoff frequency of lead.
ANS.(a)
K1= hc/ 1 – W and K2= hc/ 2 – W
Js
c
KK
h
34
12
2121
1062.6
Use 1eV = 1.6 x 10-19 J
(b) W = hc/ 1 –K1 = - 4.14eV
The cutoff frequency of the metal is
0 = W/h = 1015 Hz
Exercise(estimation of the Planck constant)
14. EM radiation with 0.01
to 10 nm x-rays
Photons transfer energy to electron: photoelectric effect
Can reverse be true?
X-rays
V
16
min
1024.1
V.m
X-ray production:
16. Compton effect
Compton scattering is another one of those really important events that
happened at the beginning of the 20th century that indicated that photons were
real. They really, like really does behave like a particle.
Large wave length small wave length collision
c
h
cos
c
h
sin
c
h
cosp
sinp
p
chp
hE
/
0
2
0
p
cmE
chp
hE
/
Incident photon
Target
electron
pp
cpcmE
2242
0
Scattered
electron
-
-
Further confirmation of
photon model
1927 Nobel
Scattering of x-rays from electrons in a carbon target and found scattered x-rays with
a longer wavelength than those incident upon the target.
17. In the original photon direction:
Initial momentum = final momentum
coscos0 p
c
h
c
h
In the perpendicular direction:
sinsin0 p
c
h
Collisions: conserve energy and conserve momentum
Elastic process
We've got to know what the energy of the photon is and what its momentum is.
Photon energy: h Photon momentum: h/= E/c
sinsin
coscos
hpc
hhpc
2222
)(cos))((2)( hhhhcp
Form the total energy expression we have:
)(2)())((2)( 2
0
2222
hhcmhhhhcp
)cos1)()((2)(2 2
0 hhhhcm
18. Compton wavelength:
cm
h
C
0
gives the scale of the wave length
change of the incident photon
cos/
sin
tan
Angle of recoil electron:
Compton effect or shift:
In order to conserve energy and momentum, I've got to have a shift in the wavelength. that
means, the outgoing photon has a different wavelength than the incoming one. this is
impossible classically. You cannot have a wave do that. But in quantum, you can.
this shift in wavelength is associated with h/mc. This is dimensionless
h/mc is really really small compared to the wavelength of light, then the shift in wavelength
is relatively really small.
If h/mc is very very large compared to the wavelength of the radiation that you're sending in
to hit the electron, then this shift in wavelength is going to be huge.
So the Compton scattering is determined by how big the wavelength of the light that you're sending in
is, in comparison to the Compton wavelength.
Small effect if >> c
Large effect if << c
)cos1(
0
cm
h
Compton wavelength is really really small. 2.4 pm. So a pm is a trillionth of a meter. So this actually is
about 100 times smaller than the atom. So you got to send in light with a really tiny wavelength, 100
times smaller than an atom in order to get an appreciable Compton scattering effect. But we've done it
and this is the way it comes out.
20. Ex-1
High energy photos (-rays) are scattered from electrons initially at rest. Assume
the photons are backscattered and their energies are much larger than the
electron’s rest mass energy, E >> mec2.
(a) calculate the wavelength shift,
(b) show that the energy of the scattered photons is half the rest mass energy of the
electron, regardless of the energy of the incident photons,
(c) calculate the electrons recoil kinetic energy if the energy of the incident photons
is 150 MeV.
ANS:
(a) Here = , wave length shift or Compton shift:
m
cm
c
cm
h
cm
h
ee
12
2
0
108.4
42
)cos1(
(b) Energy of scattered photon E :
2/2)/()/(2 2
2
2
2
Ecm
cm
hccm
cm
cmh
hchc
E
e
e
e
e
e
MeV
cm
E
cmcm
E
cmcm
E eeeee
25.0
2
)(
2
2
1
2
2222122
(c) Kinetic energy of recoil electron: Ke = E - E 150 MeV-0.25 MeV = 149.75 MeV
If E >> mec2 we can approximate by
21. Pair production
+
-
Nucleus
Photon
Electron
Positron
p
p
cosp
cosp
ch /
Electromagnetic energy is converted into matter
Energy and linear momentum could not both be conserved if pair
production were to occur in empty space, so it does not occur there
Pair production requires a photon
energy of at least 1.02 MeV.
e- or e+
m0c2 = 0.51 MeV (rest mass energy),
additional photon energy becomes K.E of e- and e+.
Pair annihilation: e- + e+ +
The pair production : direct consequences of the Einstein mass-energy relation; E = mc2.
22. Ex-1
Calculate the minimum energy of a photon so that it converts into
an electron-positron pair. Find the photon‘s frequency and
wavelength
The Emin of a photon to produce e- and e+ pair is equal to sum of
rest mass energy of both. So Emin = 2mec2 = 1.02 MeV.
The photon’s frequency and wavelength can be obtained at once
from Emin = h = 2mec2 and =c/:
= 2.47 x 1020 Hz and = 1.2 x 10-12 m
Ans:
23. Photon and gravity
H
hgH
c
h
hE 2
hE
KE = mgH
KE = 0 Gravitational behaviour of light: follows from
the observation that, although a photon has
no rest mass, it nevertheless interacts with
electrons as though it has the inertial mass
Photon “mass” 2
c
h
v
p
m
Photon energy after falling through height H
2
1
c
gH
hh
Although they lack rest mass, photons behave as though they have gravitational
mass
24. Assignment-IV
PH101: Physics-I Due Date: 28/10/2013 S. N. Dash
1. A 45 kW broadcasting antenna emits radio waves at a frequency of 4 Mhz. (a) How many photons
are emitted per second? (b) Is the quantum nature of EM radiation important in analyzing the
radiation emitted from this antenna? [2+2]
2. When a light of a given 1 is incident on a metallic surface, the stopping potential for the
photoelectrons is 3.2 V. If a second light source whose wavelength is double that of the first is
used, the stopping potential drops to 0.8 V. From this data, calculate (a) the of the first radiation
(b) the work function and cutoff frequency of the metal. [4+2]
3. Consider a photon that scatters from an electron at rest. If the Compton’s wavelength shift is
observed to be triple the wavelength of the incident photon and if the photon scatters at 60o ,
calculate (a) the wavelength of the incident photon, (b) the energy of the recoiling electron, (c)
the angle at which the electron scatters. [2+2+2]
4. What voltage must be applied to an x-ray tube for it to emit x-rays with a minimum wave length
of 30 pm (10-12 m) ? [2]
5. The distance between adjacent atomic planes in calcite is 0.3 nm. Find the smallest angle of
Bragg scattering for 0.03 nm x-rays ? [2]
6. A positron collides head on with an electron and both are annihilated. Each particle had a kinetic
energy of 1 MeV. Find the wavelength of the resulting photons. [2]