What is the charge density on the insulator?

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SUMMARY

The charge density of a spherical insulator with a radius of 3 cm and a total charge of -4.2 µC is calculated using the formula σ = total charge / volume. The volume of the sphere is determined to be 113.1 cm³, leading to a charge density of -3.714E-8 C/m³. This calculation confirms that for insulators, charge is distributed throughout the volume rather than just on the surface, differentiating it from conductors.

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  • Understanding of basic electrostatics concepts
  • Familiarity with the formula for the volume of a sphere
  • Knowledge of charge density and its significance
  • Ability to perform unit conversions (e.g., from µC to C)
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  • Review the formula for the volume of a sphere and its application in electrostatics
  • Study the differences between charge distribution in conductors and insulators
  • Learn about the implications of charge density in various materials
  • Explore advanced topics in electrostatics, such as electric fields and potentials
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Students studying electrostatics, physics educators, and anyone interested in understanding charge distribution in materials.

Luke0034
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Homework Statement



Insulator has a 3 cm radius and is a sphere. It has a total charge of -4.2 uC. I need to find the charge density of the insulator.

Homework Equations


sigma = total charge / volume... I think?

The Attempt at a Solution



After using the above equation, I got -3.714E-8 C/m

I am just not sure if this is the correct charge density for the insulator. I know that for conductors, I think the equation would be charge/area, but I think since an insulator contains the charge throughout the sphere and not just on the surface, you'd have to use volume correct? I am correct in my answer and thinking?
 
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Thinking is good, but I can't see your calculation (telepathic powers lacking) :smile: and the dimension of the answer seems a bit strange to me. Value also.
 

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