# Tagged Questions

Electrostatics is concerned with the electrical fields and scalar potentials of stationary electrical charges and charge distributions. Use this for questions about electromagnetic situations in which currents and magnetic fields are absent, otherwise use [tag:electromagnetism] and/or ...

9 views

### Dipole moment of a single point charge

Kindly refer to "MULTIPOLE EXPANSION" section of Introduction to electrodynamics by Griffiths(Chapter 3). Let us first discuss about why multipole expansion is needed. As far as I understand, if we ...
827 views

### Why is capacitance defined as charge divided by voltage?

I understand that capacitance is the ability of a body to store an electrical charge and the formula is $C=\frac{Q}{V}$. What I don't understand, however, is why it is defined as coulomb per volt. Of ...
30 views

### While deriving Coulomb's Law from Gauss' Law, the power of 'r' comes out to be exactly 2 while experiment shows that it differs about 10^(-16). Why?

While deriving Coulomb's Law from Gauss' Law, the power of 'r' comes out to be exactly 2 while experiment shows that it differs about 10^(-16). Why is it so? I'm referring to the book 'Physics by ...
40 views

### Coulomb's law and its application [on hold]

I just read that Coulomb*s Law describes (a) the forces that bind atoms together to form molecules (b) the forces that bind molecules together to form solids. My question is Do a proton share ...
155 views

### Does charge of a metal charged by induction determine by which ends of the metal is grounded to?

Does charge of a metal charged by induction determine by which part of the metal is ground to? I draw a diagram to make it simple to understand: Right diagram: When ground is touched with the ...
39 views

### Calculating the surface integral over a charged box

In a question that I'm trying to solve, we're told that there is a box with dimensions 20cm long, 4cm high, and 3cm deep. we're given that the electric field on every surface of the box is pointing ...
30 views

### Calculation of charged sphere distribution near a wall in Cartesian coordinates

I am following a similar derivation as found in the beginning of this paper "Quantitative aspects of the growth of (charged) silica spheres" by A.P. Philipse. This paper calculates the growth of a ...
18 views

### Energy (voltage) correction on energy level between metallic electrodes with dielectric and accounting for work function difference

My goal is to understand how to correct for the field drop and the work function difference when performing electrical measurements on a certain energy level of a sandwiched system. The situation is ...
30 views

### Understanding electric potential in the context of gravitational potential?

I'm trying to understand the concept of electric potential and the significance of an electric field being related to the gradient/derivative of an electric potential. I found this question that ...
23 views

### electric charges on the surface and inside a charged body [on hold]

There is a hollow object (for example an inflated balloon.it is charged. where will the charges reside? Inside the balloon or on the surface of it? Why what will be the case of a solid sphere which is ...
312 views

### Why does a point charge generate an electric field and why is an electric field represented by this formula?

Why does a point charge generate an electric field and why is an electric field represented by this formula $$E ~=~ \frac{q}{4 \pi \epsilon r^2},$$ where $\epsilon$ is permittivity of free space ...
33 views

### Self enery of a sphere [on hold]

If we have a sphere of radius 2R in which there is a cavity of radius R with concentric centre . Now we have to find self energy. I searched and got 3 methods : 1) U'' + U' + U* = U In this we ...
18 views

### Net Electrical Force

If a metal is insulated from earth and if a charged object is held near one end of it but not touched , will the net force acting on the metal be zero ?
239 views
+50

40 views

### electrostatics and elecrtic field [closed]

two opposite charges are placed and thee electric lines of forces are drawn if the angle made by the tangent at the initial point of one charge is 'a'then find the angle made by the line of force that ...
42 views

### Electric Field Vector on an insulating solid ball

An insulating solid ball with radius $R$ has a uniform charge density $ρ$. Find the electric field vector inside and outside of the ball if it has dielectric constant $K$. Normally, I'd treat ...
59 views

### Spherical Shell with Electric Field Zero Everywhere Inside It

If an isolated, charged spherical shell has a uniform charge distribution, the electric field everywhere inside it is 0, by Gauss' Law. Is the converse true? That is, given an isolated, charged ...
19 views

### Force on a charged conducting sphere due to a uniform electric field

If a charged conducting sphere is placed in a uniform electric field , will the force on it be simply qE ? I know that the electric field lines enter a conductor perpendicularly so does this have any ...
166 views

### How is Capacitance affected by a seperation distance and with or without a battery?

The questions specifically says this : A parallel-plate capacitor initially has capacitance $C$. The distance between the plates is then doubled, with a $9.0V$ battery connected. The battery is then ...
30 views

### Electric potential inside a shell

Inside a shell, electric field is zero. Then does it have a constant electric potential inside the shell? If $V=\dfrac Ed$, then since field is zero, potential should also have been zero. Please ...
16 views

### Why will the force of repulsion decrease in two conducting charged spheres when kept close to each other? [closed]

The force of repulsion between two point charges is $F$ when these are at a distance 0.1 Metre. Now the point charges are replaces conducting spheres of radii 5cm each, having the same charge as point ...
2k views

### What is the origin of the Dirac delta term in the dipole electric field?

I am a bit lost how one has deduced the formula for electric field with electric dipole because of some inconsistency between different sources. The Wikipedia article contains a delta function in the ...
2k views

### The total energy of an electrostatic system

My problem is from Griffiths Introduction to Electrodynamics, Fourth Edition, p.112 Problem 2.60 (not homework): A point charge $q$ is at the center of an uncharged spherical conducting shell, ...