All Questions
15
questions
0
votes
4
answers
44
views
Comparing Electric Potential Energy of two Charges
I do not know what I am missing here and would appreciate a little help in figuring out the flaw in my logic. I have a row of positive charges and a row of negative charges as shown in the image above....
- 1
1
vote
1
answer
147
views
Confusion pertaining to the electric potential energy
First I'd like to explain why I don't think this question is a duplicate of the many other questions about the electric potential and potential energy. Despite there being many questions and answers ...
- 125
1
vote
1
answer
122
views
The (electrostatic) force on an extended object
It is well known that, if I have a system of $N$ particles acted upon only by conservative internal and external forces, then I can obtain the force on the $\mathrm{i^{th}}$ particle as
$$\textbf{F}_i ...
- 1,095
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
0
votes
1
answer
155
views
Does electric current flow from higher potential to lower potential or from higher potential energy to lower potential energy?
Here, $O$ is a field charge with a $+T$ charge. $A$ and $B$ are test charges with $+T_1$ and $+T_2$ charge, and they are fixed in place. Suppose the points at which $A$ and $B$ are situated are $P_1$ ...
- 1,018
0
votes
3
answers
170
views
Why is the force that does the work, when calculating the electric potential energy, symmetric to the electric force? [closed]
"The electrical potential at a point is the work per unit charge required to move the charge to that point (r) from another point which has been assigned a potential of zero ($r_{0}$)". This ...
- 169
0
votes
1
answer
53
views
Why is the work through the element the same as the potential difference if we define potential difference this way?(lumped elements)
In the Feynman Lectures on Physics part ||, chapter 22-3 he defines potential differnce like this:
The picture is an element in a curicuit, the black lines on top and the bottom are the conductors, ...
- 199
1
vote
2
answers
105
views
Why is the sense of the electric field the one that goes from the highest to the lowest values of an electric potential?
To clarify, what's the reason behind it and why is it not the opposite?
- 13
0
votes
1
answer
435
views
Doubt in the interaction energy of the dipole in an electric field
Consider a dipole ($\vec{p}$) in an electric field ($\vec E$) making an angle $\theta$ with the field.
We can see that $V_1-V_2=Ed\cos\theta$
In books, the derivation for the interaction energy of ...
- 436
0
votes
1
answer
64
views
Why is the distance where electric field is zero different from the one where potential is zero?
I came across this exercise which says that in an xy plane there are two charges: q1 = q and q1 = -12q, and that q1 is at (0,0) on the plane and q2 at (0,9). I was asked to find the abscissa , which ...
- 13
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)$$
In the above, $n$ is ...
- 3,075
15
votes
2
answers
5k
views
How is energy stored in magnetic and electric fields?
We say that there is energy associated with electric and magnetic fields. For example, in the case of an inductor, we give a vague answer saying that an energy of $\frac{1}{2} LI^2$ is stored in the ...
- 7,203
2
votes
2
answers
2k
views
Using Electric Potential to Float an Object
I've been trying to answer the following question but I'm stuck at one step. The question essentially states that a magician is trying to perform a "floating objects" act, for which she has a thin ...
- 125
2
votes
2
answers
6k
views
Higher To Lower Electric Potential
The question I am working on is:
"An electron moving parallel to the x axis has an initial speed of $4.65 \cdot 10^6~m/s$ at the origin. Its speed is reduced to $1.27 \cdot 10^5 ~m/s$ at the ...
- 453
2
votes
3
answers
7k
views
Electricity & Magnetism - Is an electric field infinite?
The inverse square law for an electric field is:
$$
E = \frac{Q}{4\pi\varepsilon_{0}r^2}
$$
Here: $$\frac{Q}{\varepsilon_{0}}$$
is the source strength of the charge. It is the point charge divided ...
- 383