Electric field strength Definition and 135 Threads

Homework Statement Two isolated point charges, -7 μC and +2 μC, are at a fixed distance apart. At which point is it possible for the electric field strength to be zero? (A)......(B)...(C).....(D) o----------------------o----------o---------------o ......-7 μC...+2 μC...

(Sorry for the typo in the title. I don't know how to get rid of it) Recently I was looking at the Lorentz co-variance of F=dA (the Faraday 2-form) and *F=*dA (the Maxwell 2-form). I realized that Lorentz co-variance implies that the electric field strength and magnetic field strength are...

1. The problem is in the attachments. 2. Field strength is equal to voltage divided by distance 3. I want to make sure that i understand a few things before i solve this problem! i would like to know your opinion! a) first, field strength is inversely proportional to the the distance squared...

So let's say I'm computing the torque as a result of the interaction between two electric dipoles in the lab frame. Let's imagine they are in some electric field. I then do : τ = r×F If I now switch to the centre of mass frame I have to find their position vectors from the COM. Why do...

Homework Statement See images Homework Equations See images The Attempt at a Solution I have tried parts C and D several times, and the homework program is telling me that it's still not correct. For C, I keep getting: 7.7x10^8 N/C for D I keep getting: 7.1x10^-12 N/C...

Homework Statement I'm pretty sure I have done questions 1 to 4 correctly, it is just question 5 I am struggling with. I have an exam in one week and this is revision so it will not get marked by a tutor, and it would really help if someone could give my answers a quick check and help me...

Homework Statement Two 2.0cm diameter disks face each other, 1.0mm apart. They are charged to -10nC and 10nC. -What is the field strength between the disks? -A proton is shot from the negative disk toward the positive disk. What launch speed must the proton have to just barely reach...

As my knowledge of an electric field strength becomes more precise, what physical quantity becomes correspondingly less precisely known?

Homework Statement Three positive charges, A, B and C, of 3 × 10-6, 2 × 10-6, and 3 × 10-6 Coulombs respectively, are located at the corners of an equilateral triangle of side 0.2 meters. Find the magnitude in Newtons/Coulomb of the electric field at the center of the triangle...

The electric field strength inside a conducting charged sphere is zero, but why? In the book it says "that the field lines would link charges of opposite sign in the sphere and such a state of affairs is impossible under static conditions in a conductor." I don't really get this sentence. And...

Homework Statement Find the electric field strength at point P, which is located midway between charges A and B. The charges are separated by 20 cm. The first charge has a charge of 20 micro coulombs. The second charge has a charge of -30 micro coulombs. Homework Equations Electric...

Homework Statement What are the strength and direction of an electric field that will balance the weight of a 1.0g plastic sphere that has been charged t0 -3nC ? Homework Equations E= F/q The Attempt at a Solution Newton's laws on the charged sphere ƩFnet(y) = F -mg=0...

A VDGG is used to produce a large PD. The dome of the generator has a radios of 0.15m. It is charged and gets a PD between the dome and the Earth of 75kV. The charged stored on it is : 5.0 x 10-6C Answer: Use of E = Q/4∏εr0. 3.0 x 105 My attempt: E = kQ/r2 = 8.99 x 109 x 5.0 x 10-6 /...

Homework Statement The graph in the figure shows the electric field strength (not the field lines) as a function of distance from the center for a pair of concentric uniformly charged spheres. Which of the following situations could the graph plausibly represent? (There may be more than one...

Homework Statement draw equipotential lines and electric field lines for the following arrangements of charges: a) +4 at (3,5) b) +4 at (3,5) and +4 at (6,5) c) +4 at (3,5) and -4 at (6,5) d) +5 at (3,5) and -2 at (6,5) e) +4 at (3,4), (7,4), and (7,7) f) +4 at (3,4) and (7,4) and -4 at...

Page 10 part (b) (ii) <click on the link Now, the question states : Use Fig. 4.2 to state and explain the distance x at which the rate of change of potential with distance is maximum Now electric field strength = negative potential gradient So in effect they're asking for the point at...

Given a solid metal sphere where all the positive charges are distributed evenly on the surface of the metal sphere. My textbook says that there is no electric field strength in the middle of the metal sphere because the charge = 0. However, my understanding is that wouldn't the center of the...

Homework Statement Q. A metal sphere of radius 20 cm carries a positive charge of 2.0 μC. a. What is the electric field strength at a distance of 25 cm from the centre of the sphere? b. An identical metal sphere carrying a negative charge of 1.0 μC is placed next to the first sphere. There...

Homework Statement 2 point charges are situated 45nm apart in a vacuum. Charge A is +8μC and charge B is -25μC. X is a point 8nm from A. Calculate the electric field strength at point X only due to A (Ans is 1.2 x 10^9 N/C) Calculate the overall electric field strength at point X due to...

Hi, Four point charges of equal magnitude are held at the corners of a square. The length of each side of the square is 2a and the sign of the charges are the following: Two positive charges on the top two corners of the square and two negative charges on the bottom two corners of the square...

Homework Statement How do I calculate the Field Strength if I know the Potential? Homework Equations E = -\nablaV V = Electric Potential E = Electric Field Strength The Attempt at a Solution There's a problem in which I calculated the Potential, it's constant however. So according...

Homework Statement An infinitly long conducting cylinder of Radius R carries a inform surface charge of (lambda per unit length) determine the electric field strength inside and outside the cylinder Homework Equations integral (E.ds)= q/e0 The Attempt at a Solution im not really sure what...

When Calculating Electric Field Strength using Q/kr^3, if the Q is negative is this negative disregarded? If not this would make E around a negative charge, negative. But if a positive test charge (q) is placed between two charges (Q1(negative) and Q2(positive)) then for Q1 (the negative charge)...

Homework Statement (This was part of an assignment that we had to create, so the question is one of my own, although I'm not quite comfortable with this area, hence why I'm asking for help) Calculate electric field strength of a positive point charge of 1.3x10-7C that is 5.3x10-4m away from a...

Homework Statement Hey everyone, I'm just studying some physics, and came across this question where I don't know why I'm wrong =( It's from Physics (5th Ed.) by Halliday, Resnick and Krane - Chapter 27, Exercise 22 Positive charge is distributed uniformly throughout a long, nonconducting...

Homework Statement A wire carries a current and consists of three sections with different radii. Rank the sections according to the following quantities, greatest first: (a) current, (b) magnitude of current density, and (c) magnitude of electric field. Homework Equations i =...

Homework Statement An electron is launched at a α=38.5° angle and speed of 4.12×10^6 m/s from the positive plate of the parallel plate capacitor shown. If the electron lands d=3.03 cm away, what is the electric field strength inside the capacitor? Homework Equations t = d/v v0y =...

Homework Statement A coaxial cable has an inner core diameter 6mm and inner diameter of the outer sheath is 20mm. There are two layers of insulation between the conductors, the inner layer from a radius of 3mm to 9mm has relative permittivity of 8 while the outer layer from radius 9mm to...

What are the magnitude and direction of the electric field strength at point Z in the following: Point X, q1 = -2.0 x 10^-5 and it is 60 cm to the left of point Y, q2 = 8.0 x 10^-6, which is 30 cm to the left of Z. Essentially, this is what it looks like: X-------Y--Z

Dear physicists, I am desperate. I am using a QM code to propagate a wavefunction of a system that experienced an electric field pulse. However, in literature all values for the electric field strength are given in V/m but the program asks for W/cm^2! I am kind of very confused here and did not...

Hi all I am looking to measure minute changes in electric field strength. I found this article http://www.physorg.com/news74876394.html" which describes how scientists at harvard isolated a single electron in a highly evacuated, absolute zero chilled chamber and manipulated its movement using...

Hi, I am trying to work out the electric field strength associated with a number of different electronic systems at a given distance. I am able to simplify the systems so that I only need worry about the fields from a high-voltage busbar or cable. I know that electric field strength from a...

Homework Statement A + 7.3 nC point charge and a - 2.4 nC point charge are 3.5 cm apart. What is the electric field strength at the midpoint between the two charges? Homework Equations E = 9*10^9(q/r^2) q = charge r = distance from point charge The Attempt at a Solution Since...

Homework Statement "A copper cable carrying 50A current has radius 0.003m. What is the electric field if copper has a resistivity of 1.7x10^-8 Ohm/m?" Homework Equations Formula for current density etc. The Attempt at a Solution So I write: \vec{\mathbf{J}} = n|q|v_d = \frac{I}{A}...

Hi everyone I just need some help with this question. Its a simple one I'm pretty sure. Homework Statement A solid sphere of radius 3 cm is made from a conductor and has a charge of + 4 uC placed upon it. What is the electric field strength 1 mm from the centre of the sphere? Homework...

I have to construct an experiment which measures the electric field strength at various distances from a charged Van Der Graaff generator. How would i go about this?

Homework Statement http://img219.imageshack.us/img219/3310/problemi.png Homework Equations F = kq/r^2 The Attempt at a Solution O ----- x ----O -----------O Let the electric field of the first O be E1, second be E2, third be E3. RED - .02m BLUE - .016m GREEN - .033m E1...

1. Estimate the electric field (strength and direction) at the point A. 5cmx5cm gridL 2. E = -dV/ds 3. I had four options, each a combination of 500 or 1000V/m for the E field strength and then left or right for the direction. I knew it must be to the left because the field...

Homework Statement What is the relationship between electric field strength and the potential gradient? Homework Equations The Attempt at a Solution This is my Calc based Physcis lab question but I am at a total loss. I do not understand what potential gradient is in the...

Limit Problem --- Electric field strength of an infinite line of charge Homework Statement What is the limit of the following equation? Homework Equations \stackrel{lim}{L\rightarrow\infty} \frac{K|Q|}{r\sqrt{r^{2}+(L/2)^{2}}} The Attempt at a Solution The book gives an answer...

1. Homework Statement The electric field strength 7.79 cm from a very long charged wire is 2660 N/C. What is the electric field strength (in N/C) 12.7 cm from the wire? 2. Homework Equations E= (9*10^9) Q/ r^2 3. The Attempt at a Solution i have energy. so is tried to solve...

Homework Statement The electric field strength 8.05 cm from a very long charged wire is 1310 N/C. What is the electric field strength (in N/C) 30.0 cm from the wire? Homework Equations E=F/Q E=KQ/R^2 The Attempt at a Solution First I try to find the charge using E=KQ/R^2...

Homework Statement This is a question on a past paper of a second-year undergraduate physics paper. A parallel plate capacitor is charged and the voltage increases at a rate of dV/dt. The plate radius is R and the distance between the plates is d. (a) What is the electric field...

It is not a homework problem, thought it can kinda be. But when they show you a diagram with object A and B, If the electric field point towards A and away from B. Does that mean that A is + and B is -?

Homework Statement - How much is the electrical voltage U between two evenly electrified parallel flat plates, distanced d = 1 cm, if the strength of electric field between them is E = 1 V / m? - - What is the strength of electric field to the left and to the right of each plate? - What is...

Hey i worked out this answer for the electric field strength at a point due to three point charges. E = -46736i + 46736j -39546k How do i convert this to V/m? eg. 12345 V/m I have checked everywhere Thanks for any help

Homework Statement In such a picture, http://i1021.photobucket.com/albums/af335/hectoryx/electrostaticequilibrium_1.jpg Induced charges will emergence on the left and right side of non-perfect conductor B, because the effect of the electric field of conductor A. As is known to all, when...

If the electric field lines are curved as opposed to straight, say from straight parallel lines parabolic curves develop, would there be any change in the field strength? ie would it be stronger when the lines are parallel than when they curve?

Lets say I have a point charge X placed on a region between a +Q test charge and +2Q point charge where electric field strength is zero. Since E=-dV/dR, does it mean V=0 or constant? Can the point charge move if i place it there? Well let's just ignore gravitational field/force here.

what are the components to find the magnitude of the electric field strength when only potential difference and that there are two oppositely charged plates that are separated by a given distance.