Electric Definition and 1000 Threads

https://i.stack.imgur.com/hSOU2.png https://i.stack.imgur.com/wE2Iy.png https://i.stack.imgur.com/R7FKK.png cannot understand this deadtime compensation method. So I have provided the whole cut out of the section of this book. BOOK: Control of Electric Machine Drive Systems Book by Seung-Ki...

Assume I could produce a stream of calcium ions from a 2nm diameter nanotube by pushing them through the nanotube using coulomb repulsion. Assuming these coulomb repulsed ions produce a stream of entangled ions which then create a slowly emitting quasi static electric (near) field. Even if...

Hi. I believe I have what may be both a silly and or a weird query. In many Griffiths Problems based on Electric Field I have seen that a coordinate system other than Cartesian is being used; then using Cartesian the symmetry of the problem is worked out to deduce that the field is in (say) z...

I'm looking for a way to use these batteries that is safe and also useful. I've looked into buy inverters to turn them into portable battery packs but am out of my depth and don't want to create a device with serious potential fire hazards without thoroughly understanding the ins and outs and...

Hello everyone, This is in reference to fig 5.19 (screen shot attached - please read the paragraph which says "Figure 5.19 shows the..."). I don't get why the field outside of the sphere of radius ct acts as though the particle would have continued its motion. Author's words : "The field...

If we have an electromagnetic wave like the one in the picture and a molecule which is, in the image, the small black ball with electron cloud being the part with "minus sign" in it, does the molecule with its cloud start to oscillate, once the EM wave hits it, as an induced electric dipole...

I got E. 13q as the answer. That is what i did: The electric field due to +q at origin 0 should equal the electric fields of charges -3q and the new charge placed at 2x. So applying the equation above like this; k*(q) / (2^2) = -3q*k + (k*C)/ 4 solving for C the new charge added, gives 13q. I...

My attempt: We have 3 charges inside 2 +ve and 1 -ve so i just added them up. 4 + 5 +(-7) = 2q Then there is a -5q charge outside the sphere. I did 2q + (-5q)= -3q . The electric field flux formula is Flux= q/ E0 . So i got -3q/E0 which is obviously wrong : ) . After quick googling , I...

Is the electric field inside a sphere always 0? Even if we have charges on the surface?

I've already tried to calculate the potential with respect to the 3 segments and then apply superposition (V1+V2+V3). However, I was not very successful. My error I think is in the calculation of the radii, mainly of the line segment that is on the z axis. Can anybody help me? I need some light...

I could try to apply the Liénard-WIechert equations immediatally, but i am not sure if i understand it appropriately, so i tried to find by myself, and would like to know if you agree with me. When the information arrives in ##P##, the particle will be at ##r##, such that this condition need to...

In the statement encircled, what does Griffiths actually mean?

I have tried to solve the problem by setting as a condition that the electric field inside the conductor has to be 0, but in this way I have two unknowns (σ1 and σ2):

Does anyone know of prior work on the use of an electric fan to supply input air to a ramjet until the air speed is sufficient (~0.2 M) for normal operation? It's obviously possible, but might not be practical. The objective being the simplicity of a pulse jet without the vibration issues.

I've been researching water bridges and electrowetting to learn the effects of electric fields on water molecules but something continues to confuse me: if polar molecules can only rotate in an electric field, how is the water moving? Anyone familiar with this phenomenon? Any help is greatly...

Current drawn by motor = ##\frac{120-75}{90}## = 0.5 Amps The answer says the power output of the motor is 37.5 Watts. The only way I can get that answer is if P = IV = 0.5(75) = 37.5. This implies that in an electric motor, the back emf is the voltage of the motor. This confuses me because...

How come when the load is increased in an electric motor, the torque and current increase but the motor slows? Isn't how fast the motor is how much torque it has?

The figure is: I have the solution to this problem: We have two distinct branches $$V_a-V_b=\overbrace{(V_a-V_c)}^{\textrm{INI}-\textrm{FIN}}+\overbrace{(V_c-V_b)}^{\textrm{FIN}-\textrm{INI}}$$ They have different intensities: ##3\, \textrm{mA}## and ##2\, \textrm{mA}## ##V_A-V_C\rightarrow##...

What i don't understand is why we are able to replace the ring with 'two oppositely charged superposed disks'? Just trying to understand.. So we have a uniform charge which means that this'll just be a simplification of the problem than, correct? Thanks in advance.

With a capacitor with a dielectric with the battery on, ##E_{total} = E_0 + E_i## ##\frac{Q_t}{dC_t} = \frac{Q_0}{dC_0} + \frac{Q_i}{dC_i}## thus, ##\frac{Q_t}{C_t} = \frac{Q_0}{C_0} + \frac{Q_i}{C_i}## since in a battery ##V_t = V_0, V_i = 0##, so either ##Q_i = 0## or ##C_i = infinite## but...

Can anyone help me how to solve this problem ?! I am sure that my answer is not right :

How can electric vehicle deliver energy to grid? This is the one of the few block diagrams that I could see in google. Do you have better one or can you explain this one? If I am not wrong. V2G is basically giving excess charge in your EV back to the grid.

Hi everyone! I'm pretty new in this forum, I found the topics here very relevant to my physics course. And here is my question: Given the following drawing, two infinite sheets (in y and z axis) of ideal conductive material. their thickness is infinitesimal (dx->0). The electric field is...

I am confused with the solution. It says ##\vec E = \frac{\sigma}{\epsilon_0}##. Shouldn't E = ##2*\vec E = 2*\frac{\sigma}{\epsilon_0}##? Electric field of the positive plate and electric field of the negative plate.

Electric field is 0 in the center of a spherical conductor. At a point P (black dot), I do not understand how the electric field cancels and becomes 0. Electric field is in blue.

1) Why is the electric field 0 at the bottom of Gaussian surface? Isn't the electric field on both sides of the surface, pointing down and outwards like a plane of charge? see image. 2) Why does a charge distribution with cylindrical symmetry have to be infinitely long? 3) My book says a...

I am confused at this calculation of the electric flux through a trapezoidal surface. The flux in should equal the flux out. The flux in equals -E*A1 where A1 is the area of the bottom of the trapezoid. The flux out equals E*A2 where A2 is the area of the top of the trapezoid. But the two fluxes...

The solution says that the tension in the string in the negative x direction is balanced by the force of the plate on the ball (red). Why is the repulsive force of the ball on the plate (in blue) not included in this calculation?

I do not understand why electric fields cannot cross. Can't you just sum the two electric fields vectors to get a net electric field?

Does the electric field vector takes into account the field's radial direction? Usually when we calculate the electric field, we use ##\vec E = \frac{kq}{r^2}\vec j##, which is a straight line vector of a positive charge q's electric field. This electric field points from a positive charge q to...

What I don't understand is how come the electric field of the negative plane isn't pointing towards the positive plane (in blue) and cancelling out the electric field of the positive plane (in red). See image

When an electron flows through a circuit say 250V, does it mean the electron possesses 250eV at any time or does it give out a total of 250eV

It's not a homework. I came up with this problem myself. Trying to understand fundamentals of electronics. Do you know how to solve it? Is voltage somehow related to electron energy levels? What knowledge should I gain to be able to solve problems like that? Thank you! If we ground the cathode...

Hello everybody, I was visualizing the electric field radiation pattern of an antenna in a 3D EM simulation software (CST), and to see it with my eyes made me realize something I probably heard during my studies but forgot. What is the phenomenon behind what you can see below, which is the...

1)Field Lines is supposed to represent the electric field around a charge ,now we can draw infinite field lines around a charge and sinc Electric flux is No of Field Lines /area ,does it become infinite ,the whole concept of field lines is quite in the Gray Area for me ,I can in theory mark...

We can find the potential energy by finding the potential difference between the two masses. the minimum distance between the two masses is 10 cm. The maximum is 30 cm because they can be 3 string lengths apart as they repulse each other once the string is cut. So, to get potential difference...

3 cm is inside the cylinder. We can use a gaussian cylinder to enclose the inside of the cylinder up to 3 cm. Because the outer cylinder is infinite there is no flux out of the end caps with the inner cylinder. There is also no charge enclosed in the cylinder. So the electric field 3cm away from...

If I have a point charge q right outside of a gaussian surface, it makes sense that the flux is zero inside the surface because the electric field going in equals the electric field going out. However, how would the electric field be zero inside? Wouldn't it just take on the electric field of...

At point ##P(0,0'03,0'04)## the field caused by the sphere is added to the field caused by the plane. First, ##E_\sigma## $$E_\sigma=\dfrac{\sigma}{2\varepsilon_0}=\dfrac{0,2\cdot 10^{-6}}{2\varepsilon_0}=11299,44\, \textrm{V}/\textrm{m}$$ Then, ##E_0##: Because ##r<R##...

In a problem of an oscillating electric dipole, under appropriate conditions, one can find, for the potential vector calculated at the point ##\vec{r}##, the expression ##\vec{A}=\hat{k}\frac{\mu_0I_0d}{4\pi}\frac{cos(\omega(t-r/c))}{r}## where: ##\hat{k}## is the direction of the ##z-axis##...

a) $$\phi_T=\phi_F-\phi_I=10^4\cdot 4\cdot 4-10^4\cdot 4\cdot 4=0\, \textrm{Nm}^2/\textrm{C}$$ b) $$\phi_F=\underbrace{300\cdot 4}_{\vec{E}}\cdot \underbrace{4\cdot 4}_{\textrm{area}}=19200\, \textrm{Nm}^2/\textrm{C}$$ $$\phi_0 = 300\cdot 0\cdot 4\cdot 4=0\, \textrm{Nm}^2/\textrm{C}$$ Then...

I have the calculation of the electric field created by a ring of radius ##R## uniformly charged with a linear density of charge ##\lambda## at any point on the axis perpendicular to its surface (##z## axis), but I have some doubts about it. I'll leave you the calculation done first: In ##x##...

Draw a Gaussian pill box that starts from 0 (half way between the slab) and extends towards 2 cm.$$A \times \int_{0}^{0.02} \rho dz$$ I'm not sure if I should multiply the integral by A (area) or V (volume) And if area would I multiply by 0.02^2? I'm confused here. Thanks for your help.

Hey, I have a really short question about electrostatics. The boundary conditions are : \mathbf{E}^{\perp }_{above} - \mathbf{E}^{\perp}_{below} = -\frac{\sigma}{\varepsilon_{0}}\mathbf{\hat{n}} , \mathbf{E}^{\parallel }_{above} = \mathbf{E}^{\parallel}_{below}. My question is what is...

define charge at an infinitesimal length of arc $$dQ = \lambda R d \theta$$We only care about the x component of the electric field because the y components cancel due to symmetry $$dE_x = \frac{k_e dQ}{R^2} cos \theta$$ Integrate to add up the infinitesimal parts. A quarter circle means 90...

I am able to get V1 = kq/a - 4kq/b and V2 = kq/b + -4kq/b For some reason the solution says it is V1-V2 as opposed to V2-V1. Maybe has something to do with positive shell in the center and negative outer shell? I know the electric field goes from positive to negative, but I don't know how...

We know the net force on the charged particle in the uniform electric field pointing up is mg - qE. To get acceleration, divide the net force by mass to get g - qE/m Plug into kinematic equation and get velocity by itself and substitute$$\sqrt{h(2g - \frac{q \sigma}{\epsilon_o m})}$$

λ1 = 3 microC/m λ2= -4 microC/m __________ . __________ l----L1---l-a1-l-a2-l-----L2---l (Not to scale) L1 = length of rod 1 (1m) a1 = length of end of rod 1 to point (0.7m) L2 = length of rod 2 (1m) a2 = length of end of rod 2 to point (0.3m) k = e field constant...

This is the question ... I have it's solution ... My problem : I can't understand why dx=R/cos^2(teta) dteta I have thought many hours but I couldn't find it's reason ... Can anyone please help with this ?!

Hi ... How can I find the electric field due to a thin circular ring of radius a and charge q for points outside the plane of the ring? The distance from the center of the ring to the point of the electric field is large compared to the radius of the ring. I have answered it but I don't know if...