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Suppose the charged sphere is made from a conductor, rather than an insulator. Do you expect the magnitude of the force between the point charge and the conducting sphere to be greater than, less than, or equal to the force between the point charge and an insulating sphere

User Samra
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1 Answer

28 votes
28 votes

Answer:

* Point charge outside the radius of the sphere r> R, the force in the two systems is the same

* Point charge inside the sphere r <R, therefore the force in the system with the insulating sphere is greater

Step-by-step explanation:

To answer this question let's use the relation

F = q E

with q being the point charge and E the electric field created by the sphere.

If we use Gauss's law

The electric field flux is proportional to the wax charge within the surface.

Let's analyze our situation.

* Point charge outside the radius of the sphere

r> R

where R is the radius of the sphere and r the distance from the center of the sphere to the point charge

in this case the waxed charge for the insulating and conducting sphere is the same, therefore the force in the two systems is the same

* Point charge inside the sphere

r <R

conductive sphere.

As the charges are mobile, they are located on the surface of the sphere and there is no waxed charge within a Gaussian surface that passes through the point charge, therefore the electric field is zero and consequently the force

F = 0

insulating sphere

Charges cannot move therefore there is a fraction of charge within a surface that passes through the point charge, consequently the electric field is different from zero

Fe> 0

for this second position the force on the conducting sphere is zero

therefore the force in the system with the insulating sphere is greater

User Tomasz Rakowski
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2.8k points