Electric field Definition and 1000 Threads

Homework Statement Homework EquationsThe Attempt at a Solution Uniform polarization : ##σ_b = \vec P ⋅ \hat n ## Taking ## \vec P = P \hat x ~and ~ \hat n = \hat s ~, ~ σ_b = P \cos \phi ## Let's take a strip of width R dΦ at an angle Φ. This strip will be equivalent to a rod of linear...

Homework Statement Find the electric field of an infinitely long straight wire of charge ## \lambda## C/m at a point ##r= ix+jy## Homework Equations ##\int E.da = \frac {Q}{\epsilon_0}## ##E= \frac{\int dq}{4\pi\epsilon_0 r^2} ##r The Attempt at a Solution Drawing a cylindrical gaussian...

Homework Statement Homework Equations ##σ_b = \vec P ⋅\hat n The Attempt at a Solution The polarized system could be transformed into two charged discs S1 and S2 of radius a kept at a distance L. The discs S1 and S2 have surface charge densities -P and P respectively. A) For L>>a, In...

Hi everyone. I need to calculate E-field(AC source / DC/ point charges) in leaky capacitor( epsilonr= a dielectric with relative permittivity and finite conductivity). But I do not how to calculate or write the equations for them. any idea or reference is very welcome.

Homework Statement A very thin, finite, and uniformly charged line of length 10 m carries a charge of 10 µC/m. Calculate the electric field intensity in a plane bisecting the line at ρ = 5 m. Homework EquationsThe Attempt at a Solution Not sure why I'm not getiting this but I've been at this...

I am trying to sketch the electric field E in snapshot of a linearly polarized laser beam. Is it correct that the E vectors bend from vertical to longitudinal near the cylindrical surface of the beam, and that all field lines within a half wave segment are closed loops?

Homework Statement Homework EquationsThe Attempt at a Solution E=kq/d2 how do I involve the kinetic energy K in the equation?

Homework Statement Homework EquationsThe Attempt at a Solution E=kq/r2 so when the distance increase E should decrease? I know this is wrong, but can someone explain why? Thanks

Hi, I'm reading the textbook and there is my image. http://imgur.com/a/9BqHm It says "The field vector E bar is tangent to the electric field line at each point". I might want to ask what "tangent" means in this sentence? Sorry to ask that stupid question.

Hello everybody I got really confused. I want to calculate the Electric-Field of an alternating current source( Sine(wt)). I do not know what is its equation. I need to run it in Matlab to get a result. Can you please give me some hints? I need to write the equation to calculate the E-field in...

Homework Statement Exercise in integration: Using the Electric Field E of a straight line segment of charge, find the electric field at height 10 cm above the centre of a rectangle of sides 10cm and 20 cm carrying charge density 4 μC/m2. Homework Equations µ=Q/L µ = charge density Q = total...

Homework Statement A + q = 5 pC charge is uniformly distributed on a non-conducting sphere of radius a= 5 cm , which is placed in the center of a spherical conducting shell of inner radius b = 10 cm and outer radius c = 12 cm. The outer conducting shell is charged with a -q charge. Determine...

Homework Statement A sphere of radius R has total charge Q. The volume charge density (C/m^3) within the sphere is ρ = ρ_0 (1 - r/R). This charge density decreases linearly from ρ_0 at the center to zero at the edge of sphere. a. Show that ρ_0 = 3Q/πR^3. b. Show that the electric field inside...

Homework Statement Consider a conductor wire with a charge Q uniformly distributed, shaped in the form of an arc of radius R and amplitude 2A (were A is a given number between 0 and π). Find the value of the electric field in the center of the arc. Homework Equations ##E(P)= \int K_e...

Homework Statement Homework EquationsThe Attempt at a Solution I tried to use the formula: F=kq1q2/r2 So at point B, the electric field strength is( 2kQ/r2) - (-kQ/r2)= 3kQ/r2 At A: (2kQ/r2)+(-kQ/r2)=kQ/r2 At C: -(2kQ/r2)-(-kQ/r2)=-kQ/r2 So B is the strongest? Is there an easier way to do it?

One side of a plate has a uniform positive charge density. Two of those plates are placed parallel to each other in a distance away, with their charged side facing each other! The electric field between is zero then! If we put a charge there it will feel no force? I think if the charge is put...

Hi. I'm going over the discontinuity aspects of the electric field as we cross the surface charge. A pillbox Gaussian surface was drawn and the electric field for "below" is throwing me off. Can someone explain why the electric field is pointing in the same direction from both sides of the...

It can be mathematically shown by Gauss's law that it is true but physically how? In case of a symmetrical conductor(Eg Sphere,Cyllinder) there are charges uniformly distributed and field of one charge cancels out the opposite charge's field! But which are not symmetrical, for them what makes...

I am having hard time understanding the definition of work done to move a charge in an electrostatic field book says that if charge A and B sitting at some position and now if I move the charge say A towards B from arbitrary direction that force required is exactly equal and opposite to the the...

Homework Statement http://imgur.com/a/g5acE # 34 A plastic rod of length L = .24 cm is uniformly charged with a total charge of 12 x 10^-6 C. The rod is formed into a semi circle with its center at the origin of the xy plane. What are the magnitude and direction of the electric field at the...

Homework Statement Given two charged particles: 1) 5x10^-9 C, (-.03 m, 0 m) 2) -20x10^-9 C (.04 m, .02 m) find the electric field at the origin.Homework Equations F = (kQq)/r^2 E = (kQ)/r^2 The Attempt at a Solution So I know since 1)'s charge is plus, its field vector is ( (8.99x10^{-9})...

I was recently reading jackson's book of electrodynamics regarding surface charge distributions and discontinuity in electric field. I reached that part and almost didn't understand anything. I will write the whole text: One of the common problems in electrostatics is the determination of...

Homework Statement An electric field is given by Ex = 2.2x + 5x2kNC-1. Find the potential difference between two points on the x-axis at x = -2.0 m and x = 2.0 m Homework Equations ∫5x2+2.2x from -2 to 2 The Attempt at a Solution I got the answer of 27V. Solution said - negative 27V Can...

Homework Statement A 90 μC point charge is at the origin. Find the electric field at the point x3 = -35 cm , y3 = 80 cm . Express your answers using two significant figures. Enter the x and y components of the electric field separated by a comma. Homework Equations E = kQ/r^2...

Homework Statement A uniform electric field exists in the region between two oppositely charged parallel plates 1.59 cmapart. A proton is released from rest at the surface of the positively charged plate and strikes the surface of the opposite plate in a time interval 1.50×10−6 s . Find the...

Homework Statement Can there be a point in space where there is an electric potential but not electric field? Can there be a point in space where there is an electric field but no electric potential? Explain you answer. What would the electric field lines look like if the electric field was...

There is no math in this one! I just wanted to know if I had the idea correct. Homework Statement If I have two positively charged particles at a distance between them that a field is produced between and around them, will test particles that repel away be solely a function of their distance...

Homework Statement An infinite non-conducting plate of thickness ##d## lies in the ##xy## plane. The bottom surface of the plate lies in the plane ##z=0##. The charge density of the plate is ##\rho=\rho_0 z /d~,~\rho_0>0##. Find the electric field in the regions ##z<0~~,~~0<z<d~~,~~z>d## and...

I study electromagnetism and I got to the chapter about special relativity, in this chapter my professor (since we are not using the electromagnetic tensor in this course) used a specific case to show that the electric field parallel to the velocity of a frame of reference stay the same in both...

Suppose a charge q is placed at point x=0, y=0. A second charge q is placed at point x=8.0m, y=0. What charge must be placed at the point x=4.0m, y=0 in order that the field at the point x=4.0m, y=3.0m be zero?

Hi there, Im familiar with the concept that electric field has associated energy with it Now if in space an electron apppeared at some instant t=0 then electric field will not be established instantaneously but will propagate at speed of light through space As electric field is bieng...

1. The problem statement, all variables, and given/known data Suppose you have a wire of length l and a uniform line charge density λ. Find the electric field at the midpoint that is height r above the x-axis Homework Equations (see attached) The Attempt at a Solution To solve, I used the...

So, I was studying force between the plates of a capacitor when a dielectric is inserted. Here is my question https://ibb.co/cenvXk Shouldn't it be like this picture below https://ibb.co/kOUsCk So, why is my teacher saying that the electric field inside the dielectric cancelling. So, what...

Hi Guys, I've been learning electric field, and i want to ask about this question.EF net = EF1 + EF2 my EF1 = 9 x 109 * 4 x 10-8 / (0.6)2 = 1 x 103 (From Q1) EF2 = 9 x 109 * 2 x 10-8 / (0.3)2 = 2 x 103 (From Q2) then EFnet = (2+1) x 103 = 3 x 103 and what i get from key answer is 2.2 x 103...

Hello, I think I solved the question, but I am confused by the elaboration on the exercise given by my professor. 1. Homework Statement A very large plate charged with charge Q is placed between x = -d and x=0. A similar plate charged with charge 3*Q/2 is placed between x = 3*s and x = 3*s +...

Homework Statement Consider a straight line segment of 3L and with a linear charge density λ. Determine the electric field, E, of at point P, which is a point within the segment and along the axis. (figure attached) Homework Equations dE=kdQ/r^2 The Attempt at a Solution I attempted solving...

In this image charge q is enclosed within an arbitrary shaped conductor. I'm asked to find what if the Electric field in regions 1,2,3,4 are uniform and if the surface charge densities on the interior wall of the arbitrary shaped conductor and the hollow sphere conductor are uniform. My...

Hey How can i calculate the work done by a homogeneous electric field on a positive charge q = 7 × 10^-8 C when the charge moves from point 1 to point 2 . I have two cases: a) the charge is parallel to the Electric field; b) the displacement of the charge takes place at the angle α = 60 ° to...

Homework Statement A charged wire of negligible thickness has length 2L units and has a linear charge density λ. Consider the electric field E⃗ at the point P, a distance d above the midpoint of the wire. What is the magnitude E of the electric field at point P? Throughout this part, express...

Hey, First I want to find the electric field strength from the middle between two point charges q1 = 8nC and q2 = -6nC. The distance between the two charges is 10 cm. Then i want to find out at which point of a straight line, which runs through the two charges is the electric field strength...

Homework Statement (i) Consider a non-conducting sphere of radius R with non-homogeneous charge density ρ = ρ(r) = r, where r is the radial co-ordinate. (a) Find the electric field inside and outside of the sphere(b) Find and plot the electric potential inside and outside of the sphere...

This is not a homework, but a question formed in my mind after reading my textbook. Homework Statement Consider an electron (a charged particle) on a metallic equipotential surface. We know that all the points on the surface are equipotential, thus there will be no force on charged particles...

Homework Statement There is a sample problem in my physics textbook (Fundamentals of Physics, 10th Edition by David Halliday and others) which has some confusion in it for me. Please take a look at the snapshot I took, in the attachments. Homework Equations 3. The Attempt at a Solution [/B]...

Homework Statement Given that we have q1 = -4nC on the y-axis at y=0.60m. q2 on the y-axis at y= -1.20m. What must be the sign and magnitude of q2 be for the net electric field at the origin to be: a. Zero b. 50 N/C Homework Equations E=KQ/R2 The Attempt at a Solution I used: ET = E1 + E2...

From my understand, electric field is the force emitting from a charge. This means that if a charge was placed in the vicinity of the charge that was emitting the field of force, that charge placed would experience a force from it. How does potential energy differ from this? I understand that...

Some things I did not get are, 1): In the third para, it is said that potential approaches ##\infty## at ##Q##, why ? 2): In last para, The z component of field by ##Q## is said to be ##-Qh/(r^2 + h^2)^{3/2}##, Why ? should not it be ##+Q## not ##-Q## has the charge itself is positive. 3): I...

I have learned that the electric field between parallel plates are independent of distance since E=V/d so if I increase the distance between parallel plates, the E will decrease, right? if I am right on the previous statement, then why does the electric field are independent of distance?

Homework Statement A uniform spherical charge density of radius R is centred at origin O. A spherical cavity of radius r and centre P is made. OP = D = R-r. If the electric field inside the cavity at position r is E(r), the correct statement is: 1)E is uniform, its magnitude is independent of r...

Homework Statement I'm confused about [question 16](http://image.prntscr.com/image/41a5c611927c44a7ac30104be3dd10ee.png) and [question 30](http://image.prntscr.com/image/a6aea3b9a8f04df9aca0dfe14054d4ce.png). The correct answers are e and a respectively. Homework EquationsThe Attempt at a...

Homework Statement A thin and straight metallic rod of length L is rotating about its middle point with angular velocity ##\omega## in a uniform magnetic field B. The axis of rotation is perpendicular to the length of the rod and parallel to the magnetic field. The strength of the induced...