Does distance inbetween the plates of a capacitor have an effect on its charge?

In summary, the distance between the plates of a parallel plate capacitor does affect their charge while connected to a battery. Doubling the distance while connected to the battery will result in a doubling of V=Ed and a halving of C=(elipson)(A)/d, keeping Q=CV the same. However, if the distance is doubled after disconnecting from the battery, V and C stay the same, resulting in a constant Q. These assumptions are correct, but it should be noted that if the battery stays connected, V will stay the same and Q will change, whereas if the battery is disconnected, V will change and Q will stay the same.
  • #1
letsgo
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You have a parallel plate capacitor, each with opposite charge Q, connected to a battery of some voltage.

What I'm wondering, is does the distance inbetween these plates have an effect on their charge, while connected to the battery? What about if the distance was changed after being disconnected from the battery?

What I think, is if the distance was doubled (while connected to the battery) the V=Ed would double, the C=(elipson)(A)/d would half, therefore the Q=CV would stay the same.

And if the distance was doubled after disconnected from the battery, V stays fixed, so does C, and therefore Q does as well.

Are those assumptions correct?
 
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  • #2
It's the other way around. If the battery stays connected V stays the same and therefore the charge changes. If you disconnect the battery the charge stays the same since there is no way for the charge to flow away. So V changes.
 

1. How does the distance between the plates of a capacitor affect its charge?

The distance between the plates of a capacitor has a direct effect on its charge. As the distance increases, the charge on the capacitor decreases and vice versa. This is because the electric field between the plates also decreases with an increase in distance, resulting in a decrease in the amount of charge that can be stored on the plates.

2. Does the distance between the plates of a capacitor affect its capacitance?

Yes, the distance between the plates of a capacitor is directly proportional to its capacitance. As the distance increases, the capacitance decreases and vice versa. This is due to the fact that capacitance is a measure of the ability of a capacitor to store charge, and a larger distance between the plates means a decrease in the amount of charge that can be stored.

3. Is there a maximum distance that can be placed between the plates of a capacitor?

Technically, there is no maximum distance that can be placed between the plates of a capacitor. However, there is a practical limit, as increasing the distance too much would result in a very low capacitance, making the capacitor less effective. Additionally, a larger distance between the plates would also increase the size and cost of the capacitor.

4. What happens to the electric field between the plates as the distance increases?

The electric field between the plates decreases as the distance increases. This is because the electric field is directly proportional to the charge on the plates, and as the distance increases, the charge on the plates decreases, resulting in a weaker electric field.

5. How does the distance between the plates affect the energy stored in a capacitor?

The energy stored in a capacitor is directly proportional to the distance between the plates. As the distance increases, the energy stored decreases and vice versa. This is because the energy stored in a capacitor is a function of its capacitance and the square of the voltage across it. A larger distance between the plates means a decrease in capacitance, resulting in a decrease in energy stored for a given voltage.

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