1) This document summarizes J.J. Thomson's experiment to determine the specific charge of electrons.
2) The experiment uses a discharge tube with perpendicular electric and magnetic fields to cancel out deflection of a cathode ray beam.
3) By determining the velocities needed for no deflection at different field strengths and voltages, the ratio of charge to mass of electrons (i.e. specific charge) can be calculated.
The following presentation explain about electric charge ,its properties and methods of charging a body .the presentation also explain electrostatic force
The following presentation explain about electric charge ,its properties and methods of charging a body .the presentation also explain electrostatic force
Learning Objectives
Define electric charge, and describe how the two types of charge interact.
Desribe three common situations that generate static electricity. State the law of conservation of charge.
Describe three methods for charging an object.
State Coulomb’s law
Describe an electric field diagram of a positive point charge; of a negative point charge with twice the magnitude of positive charge
Draw the electric field lines between two points of the same charge; between two points of opposite charge.
Thank you So much
This is first PPT in the electrostatics series. This PPT presents idea of charge , its various methods of production like through conduction, friction, induction. It also describes working of electroscope & concept of grounding of an insulator.
To Determine the Charge to Mass Ratio for Electron by JJ-Thomson’s MethodSachin Motwani
This demonstrates the practical method of determining charge to mass ratio. This experiment is generally undertaken in the first year of an engineering degree program.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Learning Objectives
Define electric charge, and describe how the two types of charge interact.
Desribe three common situations that generate static electricity. State the law of conservation of charge.
Describe three methods for charging an object.
State Coulomb’s law
Describe an electric field diagram of a positive point charge; of a negative point charge with twice the magnitude of positive charge
Draw the electric field lines between two points of the same charge; between two points of opposite charge.
Thank you So much
This is first PPT in the electrostatics series. This PPT presents idea of charge , its various methods of production like through conduction, friction, induction. It also describes working of electroscope & concept of grounding of an insulator.
To Determine the Charge to Mass Ratio for Electron by JJ-Thomson’s MethodSachin Motwani
This demonstrates the practical method of determining charge to mass ratio. This experiment is generally undertaken in the first year of an engineering degree program.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
3. WE ARE REALLY THANKFUL TO OUR
PHYSICS TEACHER MR.SUSHIL UPRETI SIR
AND HOD PHYSICS MR.DEVENDRA KHADKA
FOR THEIR CONTINUOUS HELP AND
SUPPORT.
3
ACKNOWLEDGEMENT
4. CONTENTS;
✘ ELECTRIC FIELD AND MAGNETIC FIELD
✘ CROSS FIELD
✘ SPECIFIC CHARGE
✘ J.J. THOMSON EXPERIMENT
✘ CONCLUSION
✘ REFERENCES
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5. ELECTRIC FIELD
Electric field is defined
as the electric force per
unit charge. The direction
of the field is taken to be the
direction of the force it
would exert on a positive
test charge. The electric
field is radially outward from
a positive charge and
radially in toward a negative
point charge.
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6. MAGNETIC FIELD
A magnetic field is a vector
field that describes the
magnetic influence on
moving electric charges,
electric currents, and
magnetic materials. A moving
charge in a magnetic field
experiences a force
perpendicular to its own velocity
and to the magnetic field.
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7. CROSS FIELD
★ The uniform electric and
magnetic fields acting
mutually perpendicular to
each other is called cross field.
★ The magnitude and direction
of both fields are so adjusted
that the deflection produced
by one field on charged
particle is cancelled by the
deflection produced by the
other.
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8. DETERMINATION OF VELOCITY IN CROSS FIELD
Consider a beam of electron is
moving with the velocity v in the
electric field ‘E’ and magnetic field ‘B’.
The force on electron due to electric
field is Fₑ = eE .
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The force on electron due to magnetic field is Fₘ =Bev
When the beam is undeflected, then
magnetic force (Fₘ) = electric force (Fₑ)
Bev = eE
or, v = E/ B .
9. SPECIFIC CHARGE
★ The ratio of charge of electron to its mass is called as
specific charge.
★ It is denoted by e .
★ It can be determined by using JJ Thomson experiment.
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m
11. J.J THOMSON EXPERIMENT
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★ The set up consists of a discharge tube with fluorescent
screen. There are two electrodes: cathode ‘C’ and anode
‘A’.
★ A uniform electric field ‘E’ is applied in downward
direction through the two horizontal metal plates P and
Q.
★ A uniform magnetic field ‘B’ is applied in inward
direction and is perpendicular to the electric field.
★ When the high voltage is applied between cathode and
anode, a narrow beam of cathode rays is emitted from
cathode to anode. This beam is allowed to pass between
two plates ‘P’ and ‘Q’ and then strikes the fluorescent
screen and luminous spot is seen. When both electric
and magnetic fields are not applied, the beam of
cathode rays moves straight and strikes at the centre 'O'
of the screen.
13. DETERMINATION OF SPECIFIC CHARGE
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When sufficient amount of potential (V) is applied between the two electrodes electrons
emitted from the cathode accelerate with velocity ‘v’ then,
When the charge particle moves under the action of electric field strength (E) it moves
towards the +ve plate and finally incident at point O, at fluorescent screen. In case of applying
magnetic field only, the charge particle deviate and finally incident .
If both magnetic and electric field are applied and their magnitude and direction is adjusted
so that the charged particles move without deviation. At this condition charge particle
incident at point O at the fluorescent screen,
Then,
We have,
14. 14
Where, B is magnetic field strength. In this case the direction of magnetic field is
perpendicular to the direction of the motion of the charged particle.
From equation (i) and (ii),
We get,
Hence, the specific charge at the electron is determined if the values of E, B and V are known.
The experimentally obtained specific charge of the electron is 1.7 ✕ 10¹¹ C/kg.
15. CONCLUSION
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In conclusion, this presentation helped us build our skills and
expand our knowledge. We hope it also taught you something
new about these topics. We would like to thank Sushil Sir and our
classmates for their patience during our presentation.