Electric fields and net charge

[caljuice]

If a sphere has a net charge of zero, then it experiences no electric field right? But if you bring a + charged rod it, the electrons experience a field and all move towards it. But the net charge for the sphere is still zero since same number and electrons cancelling out. So do we say the electric field of the sphere is still zero when the electrons clearly experience a field?

Also if an charged object is in several electric fields, but the forces cancel out (static equilbrium), do we still say that object experiences an electric field?

Thanks.

 

[cragar]

The E field inside the sphere is still zero when placed in an external field , The induced surface charges will make it cancel inside . But the polarized conducting sphere will alter the E field outside . On your second question We would say it doesn't experience an E field, It would be like being inside a hollow spherical conducting charged sphere .

 

[EnglishScient]

If a sphere has a net charge of zero, then it experiences no electric field right? But if you bring a + charged rod it, the electrons experience a field and all move towards it. But the net charge for the sphere is still zero since same number and electrons cancelling out. So do we say the electric field of the sphere is still zero when the electrons clearly experience a field?

Also if an charged object is in several electric fields, but the forces cancel out (static equilbrium), do we still say that object experiences an electric field?

Thanks.

Charge is relative, not absolute.

 

[mikelepore]

Assuming that it's a conducting sphere, when you bring the positively charged rod near the sphere, negative charges will accumulate on the surface of the sphere facing toward the rod, and positive charges will accumulate on the surface of the sphere facing away from the rod. Outside the sphere but near it, on the side facing the rod, an electric field vector E will point toward the sphere, and on the side facing away from the rod an electric field vector will point away from the sphere.

Your phrase about whether the sphere "experiences an electric field" is unusual and I don't know what it means. Do you mean "experience a force" as a result of being in the place where there is a field? The charges within in the sphere do experience such a force, and that is why they have moved to the locations on the surface where they have moved to.

 

[sardar]

I would like to clarify the concepts of electric fields and net charge. The electric field is a physical quantity that describes the force experienced by a charged particle in the presence of other charged particles. It is not dependent on the net charge of an object, but rather on the distribution of charges within the object.

In the scenario described, the sphere may have a net charge of zero, but it still has an electric field. This is because the positive charge from the rod causes a redistribution of electrons within the sphere, resulting in an electric field. However, the net charge of the sphere remains zero due to the equal number of positive and negative charges.

In the case of an object in static equilibrium, where the forces from multiple electric fields cancel out, we can still say that the object experiences an electric field. This is because the presence of the electric fields still affects the distribution of charges within the object, even though the net force is zero.

It is important to note that the concept of electric fields and net charge are related but distinct. The net charge of an object is the sum of all the positive and negative charges within it, while the electric field is a measure of the forces acting on a charged particle within the object's vicinity. Both concepts are necessary to fully understand the behavior of charged objects in the presence of other charged objects.