Linked Questions

0
votes
3answers
166 views

Understanding Capacitors [duplicate]

I cannot understand how capacitors work. Electric field is supposedly uniform between the parallel plates of a capacitor. But how? Since $E=\frac{kq}{d^2}$, shouldn't the electric field approach ...
2
votes
4answers
50k views

Force between the plates of a capacitor

As we know that the electric field between two parallel plates of a capacitor is $$E=\frac{\sigma}{\epsilon_0}$$, so the magnitude of force exerted by one plate on the other should have been $$F=QE$$. ...
2
votes
1answer
15k views

What is the electric field between and outside infinite parallel plates?

I know that Gauss's law says $$\oint_S {\vec{E} \cdot d\vec{A} = \frac{q_{enc}}{{\epsilon _0 }}}$$ and that because $\vec{E}$ is always parallel to $d\vec{A}$ in this case, and $\vec{E}$ is a ...
-1
votes
3answers
25k views

Conducting and non-conducting infinite sheets of charge have same $E$? ($E$= electric field intensity)? [closed]

From my textbook the description is given below to the image.
1
vote
2answers
7k views

Electric field between 2 parallel plates

The question state that 2 large parallel plates are a distance $d$ apart and the field at $d/2$ is $E$ if the distance between the plates are reduced to $\frac{d}{2}$ what is the field strength ...
0
votes
2answers
1k views

Principle of superposition for capacitor

In a capacitor the parallel plates of opposite charge create equal electric fields in opposite directions. We know field outside the capacitor is zero but inside the capacitor it is non zero. My ...
0
votes
2answers
2k views

Confusion about surface charge density and electric field intensity of an infinite plate

consider a plate with some thickness. If both surface of the plate have a total of q charge and the area of each surface is A then would the charge density be q/A or q/2A ? And what would be the ...
4
votes
1answer
252 views

Why is the electric field between two conducting parallel plates not double what it actually is? [duplicate]

According to here: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elesht.html We can treat two parallel plates as being a single conductor which has an electric field of $\frac{\sigma}{\...
1
vote
1answer
71 views

Electric field of electron in alternating potential

I am considering the case of an electron placed in an alternating sinusoidal potential, of frequency 13.56 MHz (frequency typically used for RF plasma generation). Suppose I have a simple 1D set up, ...
1
vote
1answer
59 views

Why is the field inside a capacitor not the sum of the field produced by each plate?

In this answer by David Z, we can read, When discussing an ideal parallel-plate capacitor, $\sigma$ usually denotes the area charge density of the plate as a whole - that is, the total charge on the ...
1
vote
1answer
41 views

Why is it that only thermal energy is available in a particle propagating throughout a space-charge layer in a plasma (not kinetic)?

In this PDF on page 5 the author explains that a particle moving through a space-charge (electron density in a plasma) gains only thermal energy. Should there not also be kinetic energy?
0
votes
1answer
18 views

Slowing down in a electron velocity selector

In an electron velocity selector, we use a positively charged plate (with a slit) to accelerate the electrons which then go through the slit and into an area with an electric and magnetic field. If ...