All Questions
Tagged with electric-fields potential-energy
142
questions
31
votes
10
answers
8k
views
How is energy "stored in an electric field"?
My physics teacher told me the statement "The energy of a capacitor is stored in its electric field".
Now this confuses me a bit. I understand the energy of a capacitor as a result of the ...
- 492
15
votes
2
answers
5k
views
How is energy stored in magnetic and electric fields?
We say that there is energy associated with electric and magnetic fields. For example, in the case of an inductor, we give a vague answer saying that an energy of $\frac{1}{2} LI^2$ is stored in the ...
- 7,203
12
votes
8
answers
3k
views
Why is the electrostatic force felt in straight lines?
When two positive charges are kept close, they get repelled in the direction of a line joining both the charges. Why is it so?
Also, why is the repulsion in a straight path?
In both the cases, the ...
- 662
12
votes
5
answers
4k
views
Why do we say that electric potential energy is stored in the electric field?
I have been learning electrostatics and came across capacitors. I don't really get why do we say energy is stored in electric field rather than in the charges upon which we or the battery does work. I ...
- 129
7
votes
7
answers
4k
views
Is it impossible to construct a Faraday cage that can block a *static* electric field?
I think the answer is yes. My reasoning is this: Imagine for argument's sake, we could have a charged negative source that has its field blocked by a Faraday cage. We can transport a positive charge ...
- 6,102
6
votes
4
answers
169k
views
Relation between Electric field and potential
I am unable to understand from this - sign comes. Which step I have done wrong?
- 135
5
votes
4
answers
1k
views
Electrical potential energy stored in vacumm for a single point charge?
I have come to know the electrostatic potential energy in vacuum is given by
$${\frac{1}{2}} \epsilon_0\int d^3x {E^2} $$ and this energy is due to the mutual electrostatic coulomb potential energy.
...
- 1,336
5
votes
2
answers
1k
views
Why does field strength follow the inverse square law but potential does not?
Either in a gravitational or electrical field, let's say an electrical field, the electrical field strength follows the inverse square law. This is fairly intuitive just due to the geometry of the ...
- 109
4
votes
2
answers
4k
views
Is there really no meaning in potential energy and potential?
I have been told all my physics life that potential energy between two mass/charge has no meaning and only their difference has meaning. The same goes for electric potential, only the difference ...
- 937
4
votes
1
answer
359
views
What does negative electrical energy signify?
When we derive the formula for potential energy caused by the torque of a dipole in uniform electrical field we get $U = -pE \cos \theta$. And my textbook tells me that the when the dipole is kept ...
4
votes
5
answers
1k
views
Electric potential and electric potential energy definitions
I was thinking about the definition of this 2 concepts and I don't know if I understand exactly what they mean.
Electric potential is just the work that must be done to bring a charge from infinity to ...
- 73
4
votes
2
answers
24k
views
When work done is taken negative in electrostatics?
Let us say a point charge Q was moved across a potential difference V, then work done would be : QV.
This work is taken negative when done external agent, Please explain when It is negative and ...
4
votes
2
answers
132
views
Is there a symmetry between scalar and vector formulas for electrostatic and gravitational potential, potential energy, field and force?
Formulas for electrostatic potential, potential energy, field and force, bearing the subscript 'E':
Electrostatic potential $V_E=\frac{U_E}{q}$
Electrostatic potential energy $U_E=k\frac{q_1\,q_2}{r}...
- 156
4
votes
1
answer
693
views
Energy Stored in a Configuration of Point Charges
Original Question:
The potential energy stored in a system of $n$ charges is:
$$\frac{1}{2}∑_{i=1}^{n}q_i ∑_{j≠i}^{n}\frac{kq_j}{r_{ij}}=\frac{1}{2}∑_{i=1}^{n}q_i \phi(q_i)$$
In the above, $n$ is ...
- 3,075
4
votes
0
answers
58
views
Energy in electric field of an electron?
I am just trying to get an intuition for the Griffiths equation no. 2.45, where work done to establish a field E is given by
Say we want to solve it for electric field due to an electron (point-charge)...
