Questions tagged [electric-fields]
For questions that utilize the concept of electric fields (commonly denoted by the letter E), or for questions whose answers likely involve electric fields. More specific than the [electricity] tag, as questions about the phenomenon & theory of electricity do not necessarily involve the discussion of fields.
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What force particle mediates electric fields and magnetic fields?
The force carrier for magnetic fields and electric fields are supposedly photons. I don't get it:
1) Wouldn't that mean that a charged particle (e.g. an electron or even a polarized H2O molecule) ...
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How can neutral atoms have exactly zero electric field when there is a difference in the positions of the charges? [duplicate]
It is said that atoms with the same number of electrons as protons are electrically neutral, so they have no net charge or net electric field.
A particle with charge cannot exist at the same position ...
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"Find the net force the southern hemisphere of a uniformly charged sphere exerts on the northern hemisphere"
This is Griffiths, Introduction to Electrodynamics, 2.43, if you have the book.
The problem states Find the net force that the southern hemisphere of a uniformly charged sphere exerts on the northern ...
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Can a magnetic field exist without an electric field present?
I know an electric field can exist without a magnetic field as in the case where you have a stationary point charge.
But, magnetic fields are created by moving charges so wouldn't you always need an ...
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What is the electric field in a parallel plate capacitor?
When we find the electric field between the plates of a parallel plate capacitor we assume that the electric field from both plates is $${\bf E}=\frac{\sigma}{2\epsilon_0}\hat{n.}$$ The factor of two ...
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Field between the plates of a parallel plate capacitor using Gauss's Law
Consider the following parallel plate capacitor made of two plates with equal area $A$ and equal surface charge density $\sigma$:
The electric field due to the positive plate is
$$\frac{\sigma}{\...
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What happens when we connect a metal wire between the 2 poles of a battery?
As I remembered, at the 2 poles of a battery, positive or negative electric charges are gathered. So there'll be electric field existing inside the battery. This filed is neutralized by the chemical ...
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Why does the voltage increase when capacitor plates are separated?
In lab, my TA charged a large circular parallel plate capacitor to some voltage. She then disconnected the power supply and used a electrometer to read the voltage (about 10V). She then pulled the ...
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Electromagnetic fields vs electromagnetic radiation
As I understand, light is what is more generally called "electromagnetic radiation", right?
The energy radiated by a star, by an antenna, by a light bulb, by your cell phone, etc.. are all the same ...
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Does a current carrying wire produce electric field outside?
In the modern electromagnetism textbooks, electric fields in the presence of stationary currents are assumed to be conservative,$$
\nabla \times E~=~0
~.$$ Using this we get$$
E_{||}^{\text{out}}~=~E_{...
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Why doesn't the voltage increase when batteries are connected in parallel?
Can you please explain the thing below?
When we add a battery in circuit then, it gives out some electric field that moves through the circuit and gives a force on electrons in conductor to produce ...
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Do extremely high-voltage power lines emit positrons?
Stretching across China, from the Xinjiang region in the west to the province of Anhui in the east, there's a ±1,100 kV high-voltage direct-current transmission system. I'm not 100% sure what "±1,...
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Purpose of Using Taylor Series and Multipole Expansion to Approximate Potential
I'm currently taking a third-year electromagnetism course (we use Griffiths), and we have begun covering approximations of our potential function, $\text{V} =\int\frac{k \text{dQ}}{\textbf{||r||}}$, ...
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Are the plates of a battery really charged?
In a zinc/copper Daniell cell correct me if I am wrong :
Zinc has 2 valence electrons. So it wants to get rid of them. To do so it sends them to the copper which needs 2 to complete its valence shell....
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Why is the field inside a conducting shell zero when only external charges are present?
In many introductory books on electrostatics, you can find the statement that the field inside a conducting shell is zero if there are no charges within the shell. For example, if we place an ...
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