Electric Potential and charge flowing between 2 spheres

• erisedk
In summary, when a large hollow metallic sphere A with a positive charge of 100 V and a smaller sphere B with a positive charge of 50 V are connected by a wire, the charge will flow from B to A. This is because the voltage will be reduced and become constant throughout the conductor, and positive charges cannot move. The negative charge will flow from B to A to balance out the excess positive charge on the outer surface of the spheres. When the two spheres are connected, they become a single conducting solid with a spherical external surface, causing the charge distribution and electric field to change.
erisedk

Homework Statement

A large hollow metallic sphere A is charged positively to a potential of 100 V and a small sphere B to a potential of 50 V. Now B is placed inside A and they are connected by a wire. In which direction will the charge flow?

The Attempt at a Solution

A is at a higher potential, B at a lower potential. So charge should flow from A to B?
Even if the potentials alter due to the placement of B inside A, A is still at a higher potential?

Positive charge will always flow from high potential to low potential.

I just googled this question, and the answer is the opposite, like I'd expected. Charge flows from B to A

Notice how I said positive charge?...

I like to think of these question with respect to positive charge. Then, when I know what direction positive charge moves, I can simply say: positive charge cannot move, therefore the negative charge must be moving in the opposite direction to make it seem as though the positive charge is moving.

I'm fairly confused here, sorry. I'm just talking in terms of positive charges here, so don't worry about negative.

By connecting the wire, you are creating a conductor. You know that the electric field anywhere in a conductor is zero. Therefore, the voltage must be constant all throughout the conductor you are now creating. This means that the voltage from the 100V sphere will be reduced and become equivalent all throughout the conductor. Since positive charge cannot move, you know that negative charge will flow from sphere B into sphere A.

Oh okay. Thanks :)

Since you seem to understand I have only 1 thing to add :)

It took me a while to rectify that electrical current is positive charges flowing.

Ahhhh, can somebody pleeeeasssseeee just tell me the answer to my question now?

cpscdave said:
Since you seem to understand I have only 1 thing to add :)

It took me a while to rectify that electrical current is positive charges flowing.

That's cute ;)

All of the excess mobile charge will move to the surface of the outer sphere.

I'll agree with Luke.Current will flow from A to B but the Negative charge will flow from B-A as negative charges move from lower potential to Higher potential.
For example.Think of a Circuit normally the current flows from higher potential to lower potential (Positive Terminal to Negative Terminal) But if we think the electron would rather move from Negative Terminal to Positive terminal.(opposite charges attract).

Okay.

my2cts said:
All of the excess mobile charge will move to the surface of the outer sphere.

The charge on the outer sphere is thus increased and therefore, so is it's potential.

Sync said:
I'll agree with Luke.Current will flow from A to B but the Negative charge will flow from B-A as negative charges move from lower potential to Higher potential.
For example.Think of a Circuit normally the current flows from higher potential to lower potential (Positive Terminal to Negative Terminal) But if we think the electron would rather move from Negative Terminal to Positive terminal.(opposite charges attract).
Sync said:
Sync said:
How to delete the other 3 posts.Can someone help me? I'm new.
Look below your post on the left hand side. There are labels:
"Edit" "Delete" "Report" "Bookmark"

Click on "Delete" and respond appropriately.
[Moderator note: The posts in question were duplicates and have been removed]

from B to A . since the negative charges will move to high positively charged plate

What @Luke Cohen , @Dennis Ngeno and @Sync are all missing is that the given potentials were for the case when A and B were separate (and presumably some distance apart). When B is placed inside A, still not connected, the potentials will change. When the two are connected, they become a single conducting solid with a spherical external surface. What do we know about the charge distribution for such? What does the field inside it look like?

Vibhor

1. What is electric potential?

Electric potential is a measure of the amount of work required to move a unit of positive charge from one point to another in an electric field. It is typically measured in volts (V).

2. How is electric potential calculated?

The electric potential between two points is calculated by dividing the work done in moving a charge from one point to the other by the magnitude of the charge. Mathematically, it is represented as V = W/Q, where V is the electric potential, W is the work done, and Q is the magnitude of the charge.

3. How does charge flow between two spheres?

Charge flows between two spheres when there is a difference in electric potential between them. This difference in potential creates an electric field, which exerts a force on the charges, causing them to move from the point of higher potential to the point of lower potential.

4. What factors affect the electric potential between two spheres?

The electric potential between two spheres is affected by the distance between the spheres, the magnitude of the charge on each sphere, and the medium in which the spheres are placed. The electric potential decreases with increasing distance and increases with increasing charge on the spheres.

5. How is electric potential related to electric charge?

Electric potential and electric charge are directly proportional. In other words, the electric potential increases as the electric charge increases, and decreases as the electric charge decreases. This relationship is described by Coulomb's law, which states that the electric potential is inversely proportional to the distance between two charges and directly proportional to the magnitude of the charges.

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