Electric fields Definition and 507 Threads

Homework Statement A π- ("pi-minus") particle, which has charge -e, is at location ‹ 5.00e-9, -5.00e-9, -6.00e-9 › m. What is the electric field at location < -5.00e-9, 3.00e-9, 5.00e-9 > m, due to the π- particle? 5e-9 is equivalent to 5*10^-9 Homework Equations E=(k*q/r^2)r-hat...

Every book seems that it is a no-brainer that electric fields are zero in a conductor, but I do not understand this. First of all why assume it is zero just because, by contradiction, any electric field will produce acceleration in charges which cannot happen when there is electrostatic...

Homework Statement I just have a couple of questions concerning electric field. Is the electric field in the direction of path zero at every point from a to b in a straight line? What about along the equipotential line joining a-b? Is the electric field in the direction perpendicular...

Probably this has an easy answer but I can't see it just now, according to the principle of relativity we shouldn't be able to tell based on physical experiments if a body is at rest or in a uniform velocity, but in the case of charged objects we seem to be able to differentiate it simply by the...

Homework Statement A coaxial cable consists of a long solid inner cylindrical conductor, radius a, and a thin outer cylindrical conductor of average radius b>a. Suppose the inner conductor has a line charge density of +lambda while the outer conductor has a uniformly distributed charge of...

Homework Statement An electron is projected at an angle of 29.1° above the horizontal at a speed of 8.29×105 m/s in a region where the electric field is E = 378j N/C. Neglecting the effects of gravity, calculate the time it takes the electron to return to its initial height, the maximum height...

1. Homework Statement Here is the picture with the arrows representing Electric Fields. a. Can you find any test charges on the xy plane? Where? b. Where can you find a magnetic field? 2. Homework Equations No idea... Amperes Law? 3. The Attempt at a Solution I just...

Homework Statement Near to the Earth's surface, a speck of dust with a charge equal to an electron experiences a uniform downward electric field of strength 100NC-1 and a uniform gravitational field of strength 9.8Nkg-1. a)draw a diagram showing the electric field pattern and the sign of...

Homework Statement heres a question out of a textbook that i can't seem to do! dry air ceases to be an insulator if it is subjected to an electric field strength of 3.3kV mm-1 or more. 1) show that the electric field strength E and the potential V at the surface of a charged sphere of a...

Homework Statement Two point charges are placed on the x axis: +5 microC charge at x=0 and +8 microC charge at x=0.9m. Where on the x-axis can a third charge be placed so that the net charge on all three charges is zero? Determine the magnitude of the third charge. Homework Equations...

I have a few questions related to finding the electric field of an object. 1. What's the difference between a conducting object (sphere, cylinder) vs. a non conducting object? Is the charge inside a conducting and nonconducting sphere both zero if the surface charge density is uniform? What...

I'm trying to calculate several stuff about the electric field generated by 2 "plaques" My main problem being that in mathematica it calculates fast for a point of the electric field generated in the Y component, but if i try to make the median of all the points in the plaque it takes way to...

[b]1. Two point charges of equal magnitude are 8.4 cm apart. At the midpoint of the line connecting them, their combined electric field has a magnitude of 45 N/C. Find the magnitude of the charges. [b]2. E=k(q)/r^2 [b]3. I've tried 45= 8.99x10^9(q)/(.084)^2 and got q to equal 35...

I've been reading a section on induced dipoles in Griffiths, It says that although an atom as a whole is electrically neutral, there is a positively charged core and a negatively charged electron cloud, and when the atom is within an electric field the nucleus is pushed in the direction of the...

Negative charge - Q is distributed uniformly around a quarter-circle of radius a that lies in the first quadrant, with the center of curvature at the origin. Find the x-component of the net electric field at the origin. Find the y-component of the net electric field at the origin.

Homework Statement An electron is released from rest in a weak electric field given by vector E = -2.40 10-10 N/C jhatbold. After the electron has traveled a vertical distance of 1.8 µm, what is its speed? (Do not neglect the gravitational force on the electron.) Dont even know where...

This isn't the normal kind of homework question, I'm more hoping you can help me fill in the missing steps from this example given by our professor in the class notes. The below example is supposed to assist me in solving my homework problem, I understand everything except the answers circled...

Hey I'm a new time member but I hope to use this forum for my college Physics 2 class, anyways: 1. Question: Two charges are D = 2.5 m apart and lie on the x-axis. What must be the magnitude of the charge on the right one, Q2, (in C) so that the electric field is zero at x = 1.75 meters. Let...

Can anyone find a website that shows you how to calculate the electric field by integration for a evenly distributed disk and a hollow ring? I tried figuring it out myself but all the websites I found skipped many steps on the math. Thanks!

"Mach's principle" for electric fields I know it's terrible to draw conclusions from similarities, and gravity and electromagnetism have a particularly bad wrap for this. I made this post recently: https://www.physicsforums.com/showpost.php?p=2841591&postcount=29 And it got me wondering if...

Homework Statement A 0.10 g honeybee acquires a charge of +23 pC while flying. (a) The electric field near the surface of the Earth is typically 100 N/C, directed downward. What is the ratio of the electric force on the bee to the bee's weight? (b) What electric field strength and...

Homework Statement An electromagnetic wave in a vacuum /w magnetic field of 265 mG. If the wave is spatially confined to a beam with a diameter of .75mm, how much energy is measured by a photodetector with an active area with diameter 5 cm in one second. The Attempt at a Solution...

Homework Statement The magnetic field is uniform and out of the page inside a circle of radius R, and is essentially zero outside the circular region (see the figure). The magnitude of the magnetic field is changing with time; as a function of time the magnitude of the magnetic field is...

I know the template needs to be used but i don't want answers i need help starting this. What equation do i use? Here is the question: In a particular region of space, the magnetic and electric fields have energy densities of 0.2 J/m3 and 4 J/m3 , respectively. Calculate the strength...

Homework Statement http://img532.imageshack.us/img532/1460/problemjh.png Homework Equations Electric field from infinite plane: E = \frac{\sigma }{2\varepsilon _{0}} The Attempt at a Solution I'm pretty sure that at region 2, the total electric field is 0 since all the charges on the...

Homework Statement 108 electrons are equally spaced around a circle of radius 10.0 cm. What is the electric field at the center of the circle? What would be the electric field be at the same location if one electron was removed? Homework Equations \begin{flalign*}E & = & & k \...

Homework Statement Each of the protons in a particle beam has a kinetic energy of 3.25 x 10^-15 J. What are the magnitude and direction of the electric field that will stop these protons in a distance of 1.25 m? Homework Equations Felectric = kC (q*q/r^2) Electric Field= Felectric/q...

Homework Statement An object with a net charge of 24 x 10^-6 Coulombs is placed in a uniform electric field of 610 N/C, directed vertically. What is the mass of this object if it floats in this electric field? Homework Equations Felectric = kC (q*q/r^2) Electric Field= kC (q/r^2) E=...

Hi People all know that a neutral atom has no net charge. Well, does that mean that it neither creates an electric field nor is affected by any electric field? I wonder whether it's correct or not, because the distance between a test charge outside this atom is closer to its electrons...

Homework Statement The magnetic component of a polarized wave of light is given by: Bx = (4.00μT ) sin[ky+(2.00×1015s−1)t] What direction does the light travel, and which axis is the polarization parallel to? Homework Equations vector E x vector B gives direction of the light wave...

Homework Statement Figure 1 shows a pair of parallel metal plates, A and B, fixed vertically 20mm apart with a potential difference of 1500V between them. (a)(i) Draw the electric field lines in the space between the plates and calculate the electric field strength at point P. (a)(ii)Sketch...

Homework Statement A proton (q = 1.6×10−19 C, m = 1.67×10−27 kg) moves at 300 ms−1 along a line midway between the x and z axes. There is a magnetic field of 1T along the x axis and an electric field of 2000 Vm−1 along the y axis. What is the force on the proton and what is its acceleration...

Jus chek out careful when we have uniform electric charge distribution along wire or a sphere etc! Is there no any interaction between the charges in that uniform distribution! then look at the capacitor we only see straight field lines from positive charged plate to the negative charged...

If an electric field causes 2 previously stationary charges to accelerate(let's say that there was something inhibiting their movement that has now been removed) toward or away from one another, what type of field is between them, electric or magnetic?

*first time posting on here* Hi, firstly I am a high school junior taking physics and I find it very interesting and plan to major in it. Now, today my teacher was explaining electric fields and said that all charged objects generate them around themselves. He then said that fields themselves...

Hi All, I'm reading about special relativity but I'm having a very difficult time trying to understand what the author is saying. Imagine a very large magnet mounted by railroad tracks such that a moving train passes through it. On a moving train is a loop of wire. Now as train passes...

Homework Statement In the figure below, an electron is shot at an initial speed of v0 = 2.25 × 106 m/s, at angle θ0 = 20.0o from an x axis. It moves through a uniform electric field = (5.04 N/C) . A screen for detecting electrons is positioned parallel to the y axis, at distance x = 3.23 m...

Homework Statement I am looking to calculate the horizontal and vertical components of an electric field at the point of the oil drop can someone tell me if I am on the correct tracks by using the following equation. Homework Equations E=kQ/r2 The Attempt at a Solution

1. Three posative charges +Q lie on the corners of a square which is rotated 45 degrees with respect to the x-axis. Calculate the electric field at the origin, in terms of the variables Q and a. I think this question is much easier than I think it is but I'm stuck on it. There is a picture...

Homework Statement The electric field midway between two equal but opposite point charges is 894 N/C, and the distance between the charges is 17.2 cm. What is the magnitude of the charge on each? Homework Equations E = Fe/q Fe = kq1q2/r^2 The Attempt at a SolutionElectric field = k*q/r^2 =...

A 40 Micro Coluomb test charge is placed in an electric field produced by a 5 Coloumb charge. It expierences a 6 Newton force. What is the strength of the electric field at this point? If the test charge has a mass of 3 x 10 ^ -20 Kg, what acceleration does it expierence? I Think I could...

Homework Statement The source charge (the magenta circle at the origin) is a positive charge. A particle whose charge is -6e-09 C is placed at location D. 1. The electric field at location D has the value < -8000, 8000, 0 > N/C. What is the unit vector in the direction of E at this...

Hi all .. I was studying this electric field due to infinite non conducting sheet having uniformly distributed positive charge..Electric field due to it is of same direction and magnitude at any point..Which is called uniform electric field!I understood why direction of field is always...

I am struggling to grasp the concept of the electric field between two opposite charges. I know that the field is strongest closest to the charge and gets weaker further away from the charge. I also know that the electric field lines go from positive to negative and that they are perpendicular...

Homework Statement 1. If two plates, 1.0 cm by 1.0 cm, with charges of −2.30 µC and +2.30 µC, what is the magnitude of the electric field at b? +++++++++++++ ...b ----------------- 2. A uniform electric field of strength E = 4.80×10^4 N/C is observed in the region adjacent to a large...

Homework Statement Two very large horizontal sheets are 4.25 cm apart and carry equal but opposite uniform surface charge densities of magnitude \sigma. You want to use these sheets to hold stationary in the region between them an oil droplet of mass 364 \mug that carries an excess of five...

Homework Statement What work is needed to move an electron from (0,5m,0) to (0,0,8m) in an electric field of E = {25, -30, 0} x 10^3 V/m? Homework Equations W = Change in U = Q* Change in V The Attempt at a Solution I calculated Change in V = -E* change in r. Change in r I got...

Throughout space there is a uniform electric field in the -y direction of strength E = 540 N/C. There is no gravity. At t = 0, a particle with mass m = 3 g and charge q = -17 µC is at the origin moving with a velocity v0 = 25 m/s at an angle θ = 25° above the x-axis. (a) What is the magnitude...

Hi Got a question, hoping someone can give a good explanation for. We all know that large static uniform electric fields have the potential to ionize. (Dielectric breakdown of Air - Static Electricity Shock). In the Quantum picture, why does this occur. Take for instance the photo...

This image confuses me a tad. We have the n-type (negative) silicon and the p-type (positive) silicon plates. We put the plates together. The electrons are in a rush to fill the positive "holes" on the p-side, and the positive holes are in a rush to to the n-side, to the electrons. Between...