Find the charge on the conducting surface

In summary, the conversation discusses the charge on the inner surface of a conducting material. The participants use equations and attempt to find the net charge within a Gaussian surface in the middle of the material. The final conclusion is that the charge on the inner surface is -15 nC, while the charge on the outer surface is -10 nC. The participants determine this by considering the field within the conducting material.
  • #1
Fatima Hasan
319
14

Homework Statement


screenshot_57.png


Homework Equations


##Q_{net}=Q_1+Q2##

The Attempt at a Solution


##Q_{net}=Q_1+Q2##
##-15 = +5 + Q_2##
##Q_2=-15-5 = -20nC##
 

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  • #2
What's the charge on the inner surface of the shell?
 
  • #3
Doc Al said:
What's the charge on the inner surface of the shell?
##-15 nC##
##5-15=-10 nC##
 
  • #4
Fatima Hasan said:
##-15 nC##
##5-15=-10 nC##
That's not the charge on the inner surface of the shell. Do this: Imagine a Gaussian surface in the middle of the conducting material. What net charge must it contain?
 
  • #5
Doc Al said:
That's not the charge on the inner surface of the shell. Do this: Imagine a Gaussian surface in the middle of the conducting material. What net charge must it contain?
##-5 nC## ?
 
Last edited:
  • #6
Fatima Hasan said:
##-5 nC## ?
No, that's not the net charge within the Gaussian surface. Hint: What's the field within the conducting material?
 
  • #7
Doc Al said:
No, that's not the net charge within the Gaussian surface. Hint: What's the field within the conducting material?
The charge of the inner surface is ##-15nC##
The charge of the outer surface is ##+5 - 15 = -10 nC##
 
  • #8
Fatima Hasan said:
The charge of the inner surface is ##-15nC##
How did you determine that?
 

1. What is the purpose of finding the charge on a conducting surface?

The purpose of finding the charge on a conducting surface is to understand the distribution of electric charge on the surface. This information is important in predicting the behavior of the surface in an electric field and in designing electrical devices.

2. How is the charge on a conducting surface determined?

The charge on a conducting surface can be determined by using Gauss's law, which states that the total electric flux through a closed surface is equal to the total charge enclosed by that surface. This means that by measuring the electric flux through a known surface, the charge on the surface can be calculated.

3. What factors affect the charge distribution on a conducting surface?

The charge distribution on a conducting surface is affected by the shape and size of the surface, the material it is made of, and the presence of other nearby charged objects. It can also be influenced by external electric fields.

4. Can the charge on a conducting surface be negative?

Yes, the charge on a conducting surface can be negative. This means that there is an excess of electrons on the surface, giving it a net negative charge. In contrast, a lack of electrons would result in a net positive charge on the surface.

5. How does the charge on a conducting surface affect its electrical properties?

The charge on a conducting surface affects its electrical properties by influencing how it interacts with external electric fields. A positive charge on the surface will attract negative charges and repel positive charges, while a negative charge on the surface will do the opposite. This behavior is important in the functioning of electrical devices and circuits.

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