Where is the electric field greatest in magnitude?

[YMMMA]

Homework Statement

In the file

Homework Equations

No equations needed

The Attempt at a Solution

I answered it C. Since I learned that at the tip there are most of the charges. Therefore, it’s the point of the greatest E field magnitude. But another tutor told me that it is a circle, and because at D its like pulled inside, that’s the point of greatest magnitude. Which of these are correct?

 

[berkeman]

Homework Statement

In the file

Homework Equations

No equations needed

The Attempt at a Solution

I answered it C. Since I learned that at the tip there are most of the charges. Therefore, it’s the point of the greatest E field magnitude. But another tutor told me that it is a circle, and because at D its like pulled inside, that’s the point of greatest magnitude. Which of these are correct?

I believe C is correct, but you should be referring to the equation that would lead you to that conclusion. Can you post the relevant equation?

 

[YMMMA]

I believe C is correct, but you should be referring to the equation that would lead you to that conclusion. Can you post the relevant equation?

I don’t know which equation you mean. But I guess you mean this

 

[berkeman]

I don’t know which equation you mean. But I guess you mean this

No, it's a vector equation involving the charge density and a property of the electric field...

Do some searching, and if you still have trouble finding it, you can click on the Spoiler below...

Spoiler

Look for the Differential form of Gauss' Law...

 

[YMMMA]

No, it's a vector equation involving the charge density and a property of the electric field...

Do some searching, and if you still have trouble finding it, you can click on the Spoiler below...

Spoiler

Look for the Differential form of Gauss' Law...

I looked for this rule, but I don’t understand why would I use a rule to answer the question? Is it because it is more dense at the tip, so greater electric field?

 

[berkeman]

When the Divergence of the Electric field is the greatest, what does that say about its strength? (the concentration of the E-field lines)...

https://s3-us-west-2.amazonaws.com/...tes/222/2016/02/20113035/Figure_19_07_08a.jpg

 

[YMMMA]

I looked for this rule, but I don’t understand why would I use a rule to answer the question?

When the Divergence of the Electric field is the greatest, what does that say about its strength? (the concentration of the E-field lines)...

https://s3-us-west-2.amazonaws.com/...tes/222/2016/02/20113035/Figure_19_07_08a.jpg

View attachment 232267

Aha, It's clear now. Thanks for you help!