# Tagged Questions

39 views

### Draw the charge configuration according to the electric field [closed]

I'm trying to draw the charge configuration outside the regions that lead to the given electric field patterns. Can someone show me how?
87 views

### How can I split a resultant force into its $x$ and $y$ components?

Point charge 3.5μC is located at x = 0, y = 0.30 m, point charge -3.5μC is located at x = 0 y = -0.30 m. What are (a)the magnitude and (b)direction of the total electric force that these charges ...
82 views

### Potential energy & entropy of three particles

Let me first say that I am not a physicist, but I am trying to make a simulation on my computer and I have the following question. Let's consider that we have three free charges that somehow can ...
98 views

### Infinite chain of alternating charge

The problem There is an infinite chain (1d) of alternating charges that are in a distance a from each other. That is there is one charge +q and next to it -q and so on. Now calculate how much work it ...
18 views

Given the potential field in free space: $V = \frac{100xz}{x^2 + 4}$ Assume that the z = 0 surface is a conductor and find the total charge on that portion of the conductor defined by $0 < x ... 4answers 263 views ### Charge distribution on plates$A,B,C$are$3$identical metallic plates. Initially, charges$Q$,$4Q$and$2Q$were given to$A$,$B$and$C$respectively. Find final charge distributions when$B$was earthed and$A$and$C$were ... 0answers 26 views ### Question regarding 2 conducting spheres connected by a long fine line (electric potentional) I'm having a bit of trouble understanding a pretty simple issue. Assuming I have 2 conducting spheres uniformly charged connected by a long fine line (as shows in the added photo) and im being asked ... 1answer 73 views ### Capacitor with dielectric between the plates Let's assume we have a capacitor of capacitance$C$and potential difference$U$. After charging it we disconnect it. Then we put a dielectric between the plates. I know that capacitance will increase ... 1answer 61 views ### How does this particle behave in the magnetic field? I have the above question and I have though about it every way and can't seem to find out. So what I have concluded (ignore the answers on the img) Is that the force is on the z axis because the ... 1answer 404 views ### Determining$y$coordinate of charged particle motion [closed] I've tried several different ways, with a tutor, and with other colleagues. One of my colleagues has even gone to the professor with whom he worked out an equation for the component, and it was later ... 1answer 288 views ### Finding electric field between overlapping surfaces [closed] The problem is: A sphere with radius R is centered at the origin, an infinite cylinder with radius R has its axis along the z axis, and an infinite slab with thickness 2R lies between the planes ... 0answers 232 views ### Electric potential on a uniformly charged tube A hollow cylinder, with no top or bottom, of radius$R$and length$L$is uniformly charged with density$\sigma>0$. I have to find the point on space where a point charge$q>0$has to be drawn ... 0answers 122 views ### Force and Energy of interaction of conducting sphere and point charge A completely isolated neutral conducting sphere of radius$R$is kept such that its center is at a distance of$r\left(>R\right)$from a point charge$+Q$. How can I find the force of ... 1answer 431 views ### Surface charge density relation with the radius of curvature at the surface of a conductor [closed] In a text book it was given that the surface charge density of a conductor at a particular region on its surface is inversely proportional to the radius of curvature at that region. I didn't ... 1answer 130 views ### Charge of electrons and protons I have a question which reads: "A conductor has a charge of$9.6 * (10)^{-19}$coulomb. The conductor will have- " The problem I face in this question is due to not knowing the exact value of ... 1answer 353 views ### Electric potential difference from electric field of isolated spherical conductor I'm wondering if my train of thought is correct. Say you have Point$A$which is$A$distance away from the center of an isolated spherical conductor, and Point$B$which is$B$distance away from the ... 1answer 1k views ### How can I calculate out the 'specific charge' of an atom? [closed] I know that it's charge/mass. But what steps do I take to calculate the specific charge of say, carbon-12? What about ions too? 1answer 405 views ### Are dc and ac currents produce electric field? [closed] I have four different situation and i want to learn what kind of field (electric or magnetic) each produces and which produces electomagnetic waves? 1)dc current flow in a conductor 2)ac current ... 2answers 491 views ### How do I express the interaction energy between two charged spheres? Consider two identical insulating spheres each with radius$R$and uniform charge$Q$through their volume. They are separated from their centers by a distance of$d>2R$. Here is my general ... 1answer 771 views ### Electric field outside a hollow cylindrical conducting shell [closed] Imagine that a point charge$+Q$is located at radius$R$and height$z=0$inside of an infinitely long conducting cylinder shell of inner radius$a>R$and outer radius$b$. From what we know of ... 1answer 145 views ### Electric fields problem [closed] Why is this the case.. I would have thought it would have followed the E field? 2answers 168 views ### Field lines question A friend of mine asked me this question, that is asked in an entrance examination. It shouldn't be that difficult, but I fail to find a rigorous answer for it. The figure shows three charges, that ... 1answer 677 views ### How much negative charge do I accumulate by touching the earth? The Earth carries a negative electric charge of roughly 500 thousand Coulombs (according to different sources I've seen). If I touch the Earth I should therefore pick up some of this electric charge ... 1answer 368 views ### Induced charge on sphere I have a conducting sphere ($radius = a$) at potential$V_0$. It is enclosed by another thin shell ($radius = b, b > a$) which has a charge density$\sigma (\theta) = \sigma_0 \cos(\theta)$for the ... 0answers 86 views ### Static electrical attraction [closed] Coulomb's law is used to calculate the electrical attraction between 2 charged particles, what formula do I use to calculate an electrical attraction magnitude between 2 plates? Let's assume the first ... 1answer 236 views ### Find the dielectric constant of the medium? Two point charges a distance$d$apart in free space exert a force of$1.4\times10^{-4}N$. When the free space is replaced by a homogeneous dielectric medium, the force becomes$0.9\times10^{-4}N$. ... 1answer 567 views ### Does the electric field inside a sphere change if point charge isn't in center? As i understood , if you have a point charge in the center of a hollow conducting sphere then the electric field inside it, is zero because the charge distribution is spherically symmetric. But ... 1answer 466 views ### Two capacitors sharing charge My two capacitors: I have these two capacitors ($C_1 = 3\mu F, C_2 = 4\mu F$) both initially under 19 volts. Then, I added a dielectric with$k=4$at$C_1$and entire ... 1answer 516 views ### What's the electric field with a point charge not in the center of the sphere? [closed] That's a hollow conducting sphere link My charge is at P (10uC). R = 0.15m. PS = 0.05m. DS = 0.35m. What's the electric field at point D? 1answer 76 views ### Electric charge and the distance The strength of an electric field is:$E = 200\ \mathrm{N/C}$The potential (of the test charge) is:$V = 600\ \mathrm{V}\epsilon_r=1$I need to calculate the distance between this point and the ... 1answer 417 views ### Electric Fields The problem I am working on is, "In the figure below, determine the point (other than infinity) at which the electric field is zero. (Let$q_1 = -2.45\ \mu C$and$q_2 = 6.5\ \mu C$) Here is a little ... 1answer 540 views ### Electric Field due to a charged sphere Suppose we have a spherical surface with a surface charge density varying as$cos(\theta)$. Apparently one can find the electric field both outside and inside such a spherical surface by superposing ... 1answer 287 views ### Conservation of Energy as Applied to Point Charges The following question appears to be extremely straight forward, but I can't seem to be able to obtain the correct answer. The question is: A charge Q1 = 1.3uC is at rest and is located 2.3 cm ... 1answer 698 views ### ( Legendre Generating Function) Off axis Electric Potential from an insulated disk An insulated disk, uniform surface charge density$\sigma$, of radius$R$is laid on the$x,y$plane. Deduce the electric potential$V(z)$along the z-axis. Next consider an off axis point$p'$, ... 1answer 270 views ### Semiconductor problem: how much Boron is required to establish a certain amount of charge carrier density The problem description is as follows: Boron is used to dope 1 kg of germanium (Ge). How much boron (B) is required to establish a charge carrier density of 3.091 x 10^17 / cm^3. One mole of ... 4answers 2k views ### Delta Dirac Charge Density question I have to write an expression for the charge density$\rho(\vec{r})$of a point charge$q$at$\vec{r}^{\prime}$, ensuring that the volume integral equals$q$. The only place any charge exists is at ... 2answers 6k views ### Why is electric field zero inside a hollow metal sphere ? The figure below shows a hollow metal sphere with a positive point charge$Q$sitting outside it. What is the electric field at the center of sphere ? The answer is zero (look at here at the beginning ... 2answers 788 views ### Find the quantity of charge - given potential function A potential function is given by$V(r)=\frac{Ae^{-\lambda r}}{r}$Find charge density and hence charge. I first took the gradient of potential to get$\vec{E}(r)=\frac{Ae^{-\lambda ...
520 views

I have a very simple problem: There is a charge $-q$ at $(0, 0, d)$ and $(0, 0, -d)$ as well a charge $2q$ at $(0, 0, 0)$. I have to calculate the quadrupole moment using spherical coordinates. I use ...