Electricity and magnetism Definition and 215 Threads
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force is carried by electromagnetic fields composed of electric fields and magnetic fields, and it is responsible for electromagnetic radiation such as light. It is one of the four fundamental interactions (commonly called forces) in nature, together with the strong interaction, the weak interaction, and gravitation. At high energy, the weak force and electromagnetic force are unified as a single electroweak force.
Electromagnetic phenomena are defined in terms of the electromagnetic force, sometimes called the Lorentz force, which includes both electricity and magnetism as different manifestations of the same phenomenon. The electromagnetic force plays a major role in determining the internal properties of most objects encountered in daily life. The electromagnetic attraction between atomic nuclei and their orbital electrons holds atoms together. Electromagnetic forces are responsible for the chemical bonds between atoms which create molecules, and intermolecular forces. The electromagnetic force governs all chemical processes, which arise from interactions between the electrons of neighboring atoms. Electromagnetism is very widely used in modern technology, and electromagnetic theory is the basis of electric power engineering and electronics including digital technology.
There are numerous mathematical descriptions of the electromagnetic field. Most prominently, Maxwell's equations describe how electric and magnetic fields are generated and altered by each other and by charges and currents.
The theoretical implications of electromagnetism, particularly the establishment of the speed of light based on properties of the "medium" of propagation (permeability and permittivity), led to the development of special relativity by Albert Einstein in 1905.
I'm currently in an electricity and magnetism physics course and we're using the 8th edition of Serway.
I'm looking for a review type book that focuses on problem solving with examples and explanations rather than theory.
Here are the topics we are covering throughout the course:
23...
Hello:
Many many years ago I walked away from community college with an associates degree in physics, and despite my fondness for the subject, I had to put it aside for other things.
I recently happened upon something that lead me to realize how much I had forgotten, and so I've decided to...
Yes, yes I know about the template, but these questions are so basic that I don't really know what I can show as work... Sometimes all I need for help is the relevant equation itself -.- So please don't delete or hate. Thanks!
2. http://tinyimage.net/images/50136173150204648365.png
The...
Homework Statement
What is the Kinetic Energy of an electron that passes undeviated through perpendicular electric and magnetic fields if E = 4.0 kV/m and B = 8.0 mT?
m_{e} = 9.1 \times 10^{-31} \textup{kg}
q_{e} = 1.6 \times 10^{-19} \textup{C}
Homework Equations
I got stuck doing...
How much E&M is involved in a MechE degree? I'm a high school senior in AP Physics C: E&M and I hate it with a passion. I loved Mechanics, but E&M is terrible. Would I just need to take the one required class (Physics 2), or do I need to use multiple E&M concepts throughout undergrad? I am...
I apologize, I wrote all of this out in a word processor before attempting to post it and I did not notice that there is a template for giving problems. I hope you forgive me, my posts tend to be wordy and take awhile to write; attempting to write it in the text box would result in the server...
Homework Statement
The potential caused by an array of charges in a region of space can be described by the equation V(x,y,z)=2x+xy+y2-xz2 volts, where all distances are measured in metres. If a charge of 2 mC is moved from the position r1=(1,2,0)m to r2=(3,1,0), calculate the resulting change...
Does anyone know where I can purchase the hardcover 1985 Electricity and Magnetism? Some schools, such as Caltech and MIT, still use the book; however, Caltech does not have it in their online bookstore and MIT lists an 09 edition (which I assume is an ebook?).
Some copies are floating...
I'm taking E&M next semester, and the book we use is quite good at explaining concepts, but it only has 9-12 questions per chapter. I would like to do more practice problems. We used the same book for modern mechanics (it is a two-edition set, the first is mech and the second is E&M).
Any...
? I'm just curious. Also I'm having trouble with mechanics. I feel like i have no idea how to grasp fnet and calculating it. I also REALLY REALLY REALLY suck at drawing free body diagram. Math is a walk compared to physics which feels like a marathon. I'm actually not that great with math but...
I'm taking gen. physics 2, which consists of electric fields, magnetism, stuff like that. Big difference from classical mechanics in physics 1.
I remember in calc III, I learned nothing from my professor because he didn't know how to teach. I basically learned the entire course from Paul's...
Hi guys,
I was answering some questions on my physics homework and I didn't understand why the answer was what it was...
the first question was this:
1.) A hollow uncharged metal ball hangs from a silk thread. A glass rod has been charged by rubbing with rayon. When it is brought close to...
HI,
So say you have a small ball hanging vertically below a positively charged plate. When the ball is released from rest with the string at a small angle to the vertical, it swings in periodic pendulum motion. If the ball is now positively charged, does the period increase, decrease or stay...
good afternoon, these are my problems, I already tried to solve them but my anwers isn't well:
1-the electrical potential at certain distance of a charge of 600 V. and the electrical field is 200 N/C. At what distance of this charge is it necessary to place a charge of 0.1x10 ^-6 C and the...
I'm a first year undergraduate taking my first electricity and magnetism class, and going through all the classic material: Coulomb's law, electric fields, flux, capacitors, etc. And the book I have explains the material relatively well, but I feel like I'm missing out on so much by just being...
I completely made this question up because it's related to class and it will help me understand the lesson better and more.
Explain the work of scientists and how they revolutionized scientific thought. Include Max Plank, Einstein and Michelson-Morley. The work doesn't have to be only about...
I sincerely intend for this not to be a rant, please do not take it in this way.
Well, the first half of my physics B AP class is over. We are all done with mechanics (/happyface) and now we are going to start part 2: Electricity and Magnetism. Mechanics was very hard for me. Why? I have no...
Maxwell's "A Treatise on Electricity and Magnetism"
I bought this book as a supplement to my electromagnetism I class, but the moment Maxwell goes into anything mathematical, I'm lost. The lack of illustrations and reference to many out-dated terms makes the book hard to follow. The book is a...
electricity and magnetism HELP!
hi, I am trying to studying physics 2 (electromagnetism) before next semester. the school uses college physics by serway, which is just not working for me
do you have any recommendations of books that will supplement the material on a conceptual basis? is the...
First year studying Physics at university.
I've got my first E&M assignment and it's about charged plates but the thing is, I'm certain we haven't covered most of what it is asking, and I can hardly find any (simple) explanations to what I'm meant to do or methods I'm meant to use.
I wasn't...
Feel Free to give tips or answers to any or all of these questions
Homework Statement
1. Two Point charges qa and qb are located on the x- axis at x=a and x=b on the graph of E the x-component of E.
a) What are the signs of qa and qb?
b)What is the ratio of|qa/qb|?
c) Draw a graph of...
does the fact that a moving charge creates a magnetic field, and a moving magnet creates an electric current, imply that the two are related or inverses of each other?
-Tom
Why is it that 2 wires carrying parallel current attract each other i think they should repeal imagine 2 wires carrying electrons to the left then the current is to the right, in the reference frame of the moving electrons it seems like the electrons on the other wire are not moving so the...
Okay, I will be honest, this is a homework assignment. For that matter this is the last homework assignment which is very crucial to preparing for the final. But the problem is I have 2 more finals for which I need to study for. So if you can please help me out and give a detailed solution I...
Okay, I will be honest, this is a homework assignment. For that matter this is the last homework assignment which is very crucial to preparing for the final. But the problem is I have 2 more finals for which I need to study for. So if you can please help me out and give a detailed solution I...
Okay, I will be honest, this is a homework assignment. For that matter this is the last homework assignment which is very crucial to preparing for the final. But the problem is I have 2 more finals for which I need to study for. So if you can please help me out and give a detailed solution I...
A 1.0 E -6 F capacitor has a charge of 10.0 micro C. It is connected to a 1.0 H inductor at t = 0. Compare the potential energy of the capacitor to the potential energy of the inductor at t = 10s. Which energy is greater?
I was reading Michio Kaku's book Prallel Worlds recently and I believe I saw it say that Maxwell's equations for electricity and magnetism become the same for electricity and magnetism when monopoles are introduced.
My question is, if the equations become the same then why don't we say that...
Hey, first of all, I wanted to know that if you pass an electric current through an iron rod, for example, then what would be the relationship of it's electric field and magnetic field? Will they be parallel to each other or perpendicular?:confused:
Second: suppose to fire a particle, let it...
Homework Statement
The points A,B,C are the vertices of an equilateral triangle, of side L. Two equal positive charges q are at A and B.
A)Find the electric potential at C assuming V=0 at infinity
B) Give the expression for the work necessary to bring a positive charge Q from infinity to C...
Electricity and Magnetism questions...Gauss's law, grounding..etc.
Alright so I am finally starting to understand the material, but I have a few questions.
1. An insulating spherical shell with an inner radius of 0.1cm and outer radius of 0.3 cm carries a total charge of 20nC. Use Gauss's law...
Ok, I finished my physics I calculus based class, and really I don't feel like I learned a lot or mastered the material. I would spend many minutes nearing hours trying to think over my homework but with a load of other classes and the fact that we got all the hard and I do mean hard problems...
Homework Statement
Three plastic sheets that are large, parallel and uniformly charged are placed side-by-side. The electric field strength between sheets 1 and 2 is 2x105; the electric field strength between sheets 2 and 3 is 6x105. What is the ratio of the charge density on sheet 3 to that on...
I'm a little confused about "voltage". We learned that voltage is somewhat similar to electric field: a way to refer to the potential energy of a charge A when put near charge B without actually knowing the charge of charge A. That made sense to me, but then suddenly in class (this is college...
Homework Statement
Find the average potential over a spherical surface of radius R due to a point charge q located inside. Show that in general: (EQ 1 below), where Vcenter is the potential at the center due to all external charges and Qenc is the total enclosed charge
Homework Equations...
Hello I have these two questions on electricity and magnetism which I don't understand very well these are:
(Q1) If a closed surface encloses no charge, and electric field lines cross the surface.
(Q2) Under what conditions can coloumb's law be used to find the electric field strength...
Homework Statement
Two infinitely-long lines of charge run parallel to the z-axis. One has a positive uniform charge per unit length, [lambda]>0, and goes through the x y plane at x=0, y=d/2. The other has a negative uniform charge per unit length, -[lambda], and goes through x=0, y=-d/2...
Homework Statement
Purcell 3.3: In the field of a point charge over a plane, if you follow a field line that starts at the point charge in a horizontal direction, that is, parallel to the plane, where does it meet the surface of the conductor?
Homework Equations
The problem 'hint' is...
1. wHAT ARE ENERGY SOURCES AND POWER STATIONS?
2.WHO WAS THE FIRST PERSON TO DISCOVER THE ENERGY SOURCE?
3.WHO BUILT THE FIRST POWER STATION AND WHO DISIGNED IT?
4.WHY DID HE/SHE DECIDED TO BUILD THAT POWER STATION THERE?
5.WHAT DO SOUTH AFRICANS GAIN FROM THAT POWER STATION?
6.IS THERE...
I know that electric fields generate magnetic fields (when you put a compass next to a wire that has current in it the needle moves indicating that a mag. field is present). I know that changing magnetic fields can generate electric fields or induced emf.
What does electromagnetic waves...
Hey everyone,
I have a few questions. What is the link between electricity and magnetism? Why would moving electrons(current) create a magnetic field? Why does a moving magnetic field induce a current in a conductor?
Thanks for responces.
I have a couple of questions in E&M.
a)Can anyone tell me what a coaxial resistor and a coaxial capacitor looks like? (Approx Diagram) Because I am not sure which equations apply to them since I am not sure what they look like.
b)How do I find a self energy of a charged sphere? Split it into...
Homework Statement
Two identical conducting spheres each having a radius of .5 cm are connected by a light 2.3 m long conducting wire. A charge of 53 uC is placed on one of the conductors. Assume that the surface distribution of charge on each sphere is uniform. Determine the tension in the...
Homework Statement
Five point charges on a straight line are separated by a distance of 0.01 m. For what values of q2 and q4 would the net force on each of the other three charges be zero?
q1-----q2-----q3-----q4-----q5
Where:
q1= 2x10^-6 C
q3= 1x10^-6 C
q5= 2x10^-6 C
Homework...
Lithium-6 ions (mass is 6x a proton mass) are charged Li+ ions (one extra proton). They are accelerated by 2000 volts and passed through a velocity selector with a magnetic field of 0.020T into the page. The ions follow a straight path through the selector and are then deflected onto a piece of...
A couple of questions.
1. A capacitor of capacitance C is discharging through a resistor of resistance R. When will the energy stored be equal to half its initial value?
My logic went like this:
Energy in a capacitor (U) = Q^2/2C
so: Q = (2CU)^0.5
so therefore the charge when the...
A solenoid 2.9 cm in diameter and 15 cm in length has 300 turns and carries a current of 5 A. Calculate the magnetic flux through the circular cross-sectional area of the solenoid.
-->> I tried using the equation B = u(0)NI/L to calculate magnetic field, and then putting this in the formula...