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?
What is the evidence for the "tyranny of the majority problem" in a direct democracy context?
How to create ADT in Haskell?
Is it improper etiquette to ask your opponent what his/her rating is before the game?
A social experiment. What is the worst that can happen?
Are the IPv6 address space and IPv4 address space completely disjoint?
2.8 Why are collections grayed out? How can I open them?
On a tidally locked planet, would time be quantized?
Rising and falling intonation
Biological Blimps: Propulsion
How to indicate a cut out for a product window
The screen of my macbook suddenly broken down how can I do to recover
How can "mimic phobia" be cured or prevented?
Non-trope happy ending?
What was this official D&D 3.5e Lovecraft-flavored rulebook?
lightning-datatable row number error
Does the Location of Line-Dash-Wedge Notations Matter?
Lowest total scrabble score
Terse Method to Swap Lowest for Highest?
Has any country ever had 2 former presidents in jail simultaneously?
Pre-mixing cryogenic fuels and using only one fuel tank
Basic combinatorial probability problem
Does an advisor owe his/her student anything? Will an advisor keep a PhD student only out of pity?
Is (0,1] a closed or open set?
Is it better practice to read straight from sheet music rather than memorize it?
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 33 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