Why electric field inside a cavity of a non-conducting sphere not zero?Electric Field from charged sphere within another charged sphere does not reinforce?Gauss's law in a uniform charge distribution extending infinitely in all directionsGauss Law Not Working Inside CavityHow does Gauss's Law imply that the electric field is zero inside a hollow sphere?What is the electric field intensity inside a conducting sphere when charges are asymetrically distributed over the surface?Electric field in non-uniformly charged hollow sphereFlux through hollow non-conducting sphereWhy is the electric field inside the hole non-zero?Electric field outside and inside of a sphereAre charges outside a conducting shell relevant to electric field inside the shell?
Does Doodling or Improvising on the Piano Have Any Benefits?
Does a 'pending' US visa application constitute a denial?
Is this toilet slogan correct usage of the English language?
If infinitesimal transformations commute why dont the generators of the Lorentz group commute?
Removing files under particular conditions (number of files, file age)
How could a planet have erratic days?
Basic combinatorial probability problem
How to implement a feedback to keep the DC gain at zero for this conceptual passive filter?
Fear of getting stuck on one programming language / technology that is not used in my country
Is (0,1] a closed or open set?
Is Witten's Proof of the Positive Mass Theorem Rigorous?
Melting point of aspirin, contradicting sources
Sklearn 'Seed' Not Working Properly In a Section of Code
Can I sign legal documents with a smiley face?
On a tidally locked planet, would time be quantized?
Added a new user on Ubuntu, set password not working?
Non-trope happy ending?
Biological Blimps: Propulsion
Is it improper etiquette to ask your opponent what his/her rating is before the game?
When were female captains banned from Starfleet?
Multiplicative persistence
Is it better practice to read straight from sheet music rather than memorize it?
The IT department bottlenecks progress. How should I handle this?
Are the IPv6 address space and IPv4 address space completely disjoint?
Why electric field inside a cavity of a non-conducting sphere not zero?
Electric Field from charged sphere within another charged sphere does not reinforce?Gauss's law in a uniform charge distribution extending infinitely in all directionsGauss Law Not Working Inside CavityHow does Gauss's Law imply that the electric field is zero inside a hollow sphere?What is the electric field intensity inside a conducting sphere when charges are asymetrically distributed over the surface?Electric field in non-uniformly charged hollow sphereFlux through hollow non-conducting sphereWhy is the electric field inside the hole non-zero?Electric field outside and inside of a sphereAre charges outside a conducting shell relevant to electric field inside the shell?
$begingroup$
Now consider a charged non conducting sphere of uniform charge density, and it as hole of some radius at the centre,
now suppose I apply gauss law 
as there is no charge inside the cavity: so no charge is enclosed by Gaussian sphere so electric flux is zero hence electric field is zero
But this is not true according to sources
Like this https://www.youtube.com/watch?v=H18bYW_Do0k , textbook etc.
What am I missing here ?
electrostatics electric-fields charge gauss-law
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
|
show 1 more comment
$begingroup$
Now consider a charged non conducting sphere of uniform charge density, and it as hole of some radius at the centre,
now suppose I apply gauss law 
as there is no charge inside the cavity: so no charge is enclosed by Gaussian sphere so electric flux is zero hence electric field is zero
But this is not true according to sources
Like this https://www.youtube.com/watch?v=H18bYW_Do0k , textbook etc.
What am I missing here ?
electrostatics electric-fields charge gauss-law
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
If the sphere has uniform charge density, why would you assume no charge is enclosed?
$endgroup$
– noah
8 hours ago
1
$begingroup$
Because it a cavity!!, nothing is present
$endgroup$
– user72730
8 hours ago
$begingroup$
So you mean the surface has a uniform surface charge denisty?
$endgroup$
– noah
8 hours ago
$begingroup$
On rest of sphere
$endgroup$
– user72730
8 hours ago
$begingroup$
So let me clarify. There is a sphere with a uniform volumetric charge density, and you cut out a cavity that has no charge in it?
$endgroup$
– noah
8 hours ago
|
show 1 more comment
$begingroup$
Now consider a charged non conducting sphere of uniform charge density, and it as hole of some radius at the centre,
now suppose I apply gauss law 
as there is no charge inside the cavity: so no charge is enclosed by Gaussian sphere so electric flux is zero hence electric field is zero
But this is not true according to sources
Like this https://www.youtube.com/watch?v=H18bYW_Do0k , textbook etc.
What am I missing here ?
electrostatics electric-fields charge gauss-law
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Now consider a charged non conducting sphere of uniform charge density, and it as hole of some radius at the centre,
now suppose I apply gauss law 
as there is no charge inside the cavity: so no charge is enclosed by Gaussian sphere so electric flux is zero hence electric field is zero
But this is not true according to sources
Like this https://www.youtube.com/watch?v=H18bYW_Do0k , textbook etc.
What am I missing here ?
electrostatics electric-fields charge gauss-law
electrostatics electric-fields charge gauss-law
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 29 mins ago
Qmechanic♦
106k121961225
106k121961225
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 8 hours ago
user72730user72730
173
173
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
user72730 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$begingroup$
If the sphere has uniform charge density, why would you assume no charge is enclosed?
$endgroup$
– noah
8 hours ago
1
$begingroup$
Because it a cavity!!, nothing is present
$endgroup$
– user72730
8 hours ago
$begingroup$
So you mean the surface has a uniform surface charge denisty?
$endgroup$
– noah
8 hours ago
$begingroup$
On rest of sphere
$endgroup$
– user72730
8 hours ago
$begingroup$
So let me clarify. There is a sphere with a uniform volumetric charge density, and you cut out a cavity that has no charge in it?
$endgroup$
– noah
8 hours ago
|
show 1 more comment
$begingroup$
If the sphere has uniform charge density, why would you assume no charge is enclosed?
$endgroup$
– noah
8 hours ago
1
$begingroup$
Because it a cavity!!, nothing is present
$endgroup$
– user72730
8 hours ago
$begingroup$
So you mean the surface has a uniform surface charge denisty?
$endgroup$
– noah
8 hours ago
$begingroup$
On rest of sphere
$endgroup$
– user72730
8 hours ago
$begingroup$
So let me clarify. There is a sphere with a uniform volumetric charge density, and you cut out a cavity that has no charge in it?
$endgroup$
– noah
8 hours ago
$begingroup$
If the sphere has uniform charge density, why would you assume no charge is enclosed?
$endgroup$
– noah
8 hours ago
$begingroup$
If the sphere has uniform charge density, why would you assume no charge is enclosed?
$endgroup$
– noah
8 hours ago
1
1
$begingroup$
Because it a cavity!!, nothing is present
$endgroup$
– user72730
8 hours ago
$begingroup$
Because it a cavity!!, nothing is present
$endgroup$
– user72730
8 hours ago
$begingroup$
So you mean the surface has a uniform surface charge denisty?
$endgroup$
– noah
8 hours ago
$begingroup$
So you mean the surface has a uniform surface charge denisty?
$endgroup$
– noah
8 hours ago
$begingroup$
On rest of sphere
$endgroup$
– user72730
8 hours ago
$begingroup$
On rest of sphere
$endgroup$
– user72730
8 hours ago
$begingroup$
So let me clarify. There is a sphere with a uniform volumetric charge density, and you cut out a cavity that has no charge in it?
$endgroup$
– noah
8 hours ago
$begingroup$
So let me clarify. There is a sphere with a uniform volumetric charge density, and you cut out a cavity that has no charge in it?
$endgroup$
– noah
8 hours ago
|
show 1 more comment
4 Answers
4
active
oldest
votes
$begingroup$
Gauss's Law only gives results for the integral over a whole, closed surface. This does not mean the electric field is zero. It simply means that all field lines entering the volume also exit it at some other point.
$endgroup$
add a comment |
$begingroup$
Just to add to what Noah said, the law says that the total flux through the surface is zero. To make this point clear, imagine a region of uniform electric field $vecE = E_0hatx$ along the x axis. Consider a cube of unit area faces with two of its opposite faces normal to the field. From the RHS of Gauss law we know that the flux has to be zero as there are no charges enclosed by the cube. The LHS says
$sum_n=1^6 vecEcdot vecA_n = E_0hatxcdothatx + E_0hatxcdot-hatx = 0$
Thus the flux is zero by explicit calculation as well. Remember that the electric field and area are vectors. So the relative directions are very important. If flux is zero all you can be sure of is that the extent of field lines entering is equal to that of exiting.
$endgroup$
add a comment |
$begingroup$
In the video the electric field lines are as shown in blue in the diagram below.

Let the edge of the cavity be the Gaussian surface which has no charge within it.
Consider small areas $Delta A$ on either side of the cavity as shown in the diagram in red.
Because of the symmetrical nature of the situation you can imagine that the electric flux entering the cavity through area $Delta A$ is the same as the electric flux leaving the area $Delta A$ on the right hand side.
This means that the net flux through those two surfaces is zero.
Doing the same for the whole Gaussian surface leads to the result that the net flux though the surface is zero commensurate with the fact that there is no charge within the surface.
$endgroup$
add a comment |
$begingroup$
The field of a uniformly charged shell is zero inside the shell in agreement with Gauss's law.
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "151"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
user72730 is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f468190%2fwhy-electric-field-inside-a-cavity-of-a-non-conducting-sphere-not-zero%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Gauss's Law only gives results for the integral over a whole, closed surface. This does not mean the electric field is zero. It simply means that all field lines entering the volume also exit it at some other point.
$endgroup$
add a comment |
$begingroup$
Gauss's Law only gives results for the integral over a whole, closed surface. This does not mean the electric field is zero. It simply means that all field lines entering the volume also exit it at some other point.
$endgroup$
add a comment |
$begingroup$
Gauss's Law only gives results for the integral over a whole, closed surface. This does not mean the electric field is zero. It simply means that all field lines entering the volume also exit it at some other point.
$endgroup$
Gauss's Law only gives results for the integral over a whole, closed surface. This does not mean the electric field is zero. It simply means that all field lines entering the volume also exit it at some other point.
answered 8 hours ago
noahnoah
4,01311226
4,01311226
add a comment |
add a comment |
$begingroup$
Just to add to what Noah said, the law says that the total flux through the surface is zero. To make this point clear, imagine a region of uniform electric field $vecE = E_0hatx$ along the x axis. Consider a cube of unit area faces with two of its opposite faces normal to the field. From the RHS of Gauss law we know that the flux has to be zero as there are no charges enclosed by the cube. The LHS says
$sum_n=1^6 vecEcdot vecA_n = E_0hatxcdothatx + E_0hatxcdot-hatx = 0$
Thus the flux is zero by explicit calculation as well. Remember that the electric field and area are vectors. So the relative directions are very important. If flux is zero all you can be sure of is that the extent of field lines entering is equal to that of exiting.
$endgroup$
add a comment |
$begingroup$
Just to add to what Noah said, the law says that the total flux through the surface is zero. To make this point clear, imagine a region of uniform electric field $vecE = E_0hatx$ along the x axis. Consider a cube of unit area faces with two of its opposite faces normal to the field. From the RHS of Gauss law we know that the flux has to be zero as there are no charges enclosed by the cube. The LHS says
$sum_n=1^6 vecEcdot vecA_n = E_0hatxcdothatx + E_0hatxcdot-hatx = 0$
Thus the flux is zero by explicit calculation as well. Remember that the electric field and area are vectors. So the relative directions are very important. If flux is zero all you can be sure of is that the extent of field lines entering is equal to that of exiting.
$endgroup$
add a comment |
$begingroup$
Just to add to what Noah said, the law says that the total flux through the surface is zero. To make this point clear, imagine a region of uniform electric field $vecE = E_0hatx$ along the x axis. Consider a cube of unit area faces with two of its opposite faces normal to the field. From the RHS of Gauss law we know that the flux has to be zero as there are no charges enclosed by the cube. The LHS says
$sum_n=1^6 vecEcdot vecA_n = E_0hatxcdothatx + E_0hatxcdot-hatx = 0$
Thus the flux is zero by explicit calculation as well. Remember that the electric field and area are vectors. So the relative directions are very important. If flux is zero all you can be sure of is that the extent of field lines entering is equal to that of exiting.
$endgroup$
Just to add to what Noah said, the law says that the total flux through the surface is zero. To make this point clear, imagine a region of uniform electric field $vecE = E_0hatx$ along the x axis. Consider a cube of unit area faces with two of its opposite faces normal to the field. From the RHS of Gauss law we know that the flux has to be zero as there are no charges enclosed by the cube. The LHS says
$sum_n=1^6 vecEcdot vecA_n = E_0hatxcdothatx + E_0hatxcdot-hatx = 0$
Thus the flux is zero by explicit calculation as well. Remember that the electric field and area are vectors. So the relative directions are very important. If flux is zero all you can be sure of is that the extent of field lines entering is equal to that of exiting.
answered 7 hours ago
user3518839user3518839
764
764
add a comment |
add a comment |
$begingroup$
In the video the electric field lines are as shown in blue in the diagram below.

Let the edge of the cavity be the Gaussian surface which has no charge within it.
Consider small areas $Delta A$ on either side of the cavity as shown in the diagram in red.
Because of the symmetrical nature of the situation you can imagine that the electric flux entering the cavity through area $Delta A$ is the same as the electric flux leaving the area $Delta A$ on the right hand side.
This means that the net flux through those two surfaces is zero.
Doing the same for the whole Gaussian surface leads to the result that the net flux though the surface is zero commensurate with the fact that there is no charge within the surface.
$endgroup$
add a comment |
$begingroup$
In the video the electric field lines are as shown in blue in the diagram below.

Let the edge of the cavity be the Gaussian surface which has no charge within it.
Consider small areas $Delta A$ on either side of the cavity as shown in the diagram in red.
Because of the symmetrical nature of the situation you can imagine that the electric flux entering the cavity through area $Delta A$ is the same as the electric flux leaving the area $Delta A$ on the right hand side.
This means that the net flux through those two surfaces is zero.
Doing the same for the whole Gaussian surface leads to the result that the net flux though the surface is zero commensurate with the fact that there is no charge within the surface.
$endgroup$
add a comment |
$begingroup$
In the video the electric field lines are as shown in blue in the diagram below.

Let the edge of the cavity be the Gaussian surface which has no charge within it.
Consider small areas $Delta A$ on either side of the cavity as shown in the diagram in red.
Because of the symmetrical nature of the situation you can imagine that the electric flux entering the cavity through area $Delta A$ is the same as the electric flux leaving the area $Delta A$ on the right hand side.
This means that the net flux through those two surfaces is zero.
Doing the same for the whole Gaussian surface leads to the result that the net flux though the surface is zero commensurate with the fact that there is no charge within the surface.
$endgroup$
In the video the electric field lines are as shown in blue in the diagram below.

Let the edge of the cavity be the Gaussian surface which has no charge within it.
Consider small areas $Delta A$ on either side of the cavity as shown in the diagram in red.
Because of the symmetrical nature of the situation you can imagine that the electric flux entering the cavity through area $Delta A$ is the same as the electric flux leaving the area $Delta A$ on the right hand side.
This means that the net flux through those two surfaces is zero.
Doing the same for the whole Gaussian surface leads to the result that the net flux though the surface is zero commensurate with the fact that there is no charge within the surface.
answered 4 hours ago
FarcherFarcher
51.3k339107
51.3k339107
add a comment |
add a comment |
$begingroup$
The field of a uniformly charged shell is zero inside the shell in agreement with Gauss's law.
$endgroup$
add a comment |
$begingroup$
The field of a uniformly charged shell is zero inside the shell in agreement with Gauss's law.
$endgroup$
add a comment |
$begingroup$
The field of a uniformly charged shell is zero inside the shell in agreement with Gauss's law.
$endgroup$
The field of a uniformly charged shell is zero inside the shell in agreement with Gauss's law.
answered 8 hours ago
my2ctsmy2cts
5,6972718
5,6972718
add a comment |
add a comment |
user72730 is a new contributor. Be nice, and check out our Code of Conduct.
user72730 is a new contributor. Be nice, and check out our Code of Conduct.
user72730 is a new contributor. Be nice, and check out our Code of Conduct.
user72730 is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Physics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f468190%2fwhy-electric-field-inside-a-cavity-of-a-non-conducting-sphere-not-zero%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
If the sphere has uniform charge density, why would you assume no charge is enclosed?
$endgroup$
– noah
8 hours ago
1
$begingroup$
Because it a cavity!!, nothing is present
$endgroup$
– user72730
8 hours ago
$begingroup$
So you mean the surface has a uniform surface charge denisty?
$endgroup$
– noah
8 hours ago
$begingroup$
On rest of sphere
$endgroup$
– user72730
8 hours ago
$begingroup$
So let me clarify. There is a sphere with a uniform volumetric charge density, and you cut out a cavity that has no charge in it?
$endgroup$
– noah
8 hours ago