Why Do Both Conductors in a Capacitor Acquire Equal Charge?

In summary, the conversation discusses the relationship between a battery, a capacitor made of two conductors, and the acquisition of charge. It is mentioned that both conductors acquire the same charge regardless of their size or shape, but it is unclear how this is mathematically proven. The role of a battery in charging and applying a fixed potential is also questioned.
  • #1
bananabandana
113
5

Homework Statement


A battery is connected to a capacitor made from two conductors. Why do each of the two conductors acquire the same charge,regardless of size or shape?


Homework Equations





The Attempt at a Solution


Well, I can see that this is sensible, intuitively that the charge on one will repel an equal amount of charge on the other. But I have no idea how to prove/represent this mathematically!
Thanks for help! :)
 
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  • #2
What does a battery do to charge?
 
  • #3
Apply a fixed potential to it, I suppose. But I'm not sure how that helps??
 
  • #4
How does it apply the fixed potential?
What does it do to the charge to get that potential?
 
  • #5


I can explain this phenomenon using the principles of electrostatics. When a battery is connected to a capacitor, it creates an electric field between the two conductors. This electric field causes electrons to move from one conductor to the other, resulting in a buildup of positive charge on one conductor and an equal amount of negative charge on the other.

The amount of charge that can be stored on a capacitor is determined by its capacitance, which is a property of the materials and geometry of the conductors. This means that regardless of the size or shape of the conductors, the capacitance and therefore the amount of charge that can be stored will remain the same.

Now, according to the principle of conservation of charge, the total amount of charge in a closed system must remain constant. Therefore, as electrons move from one conductor to the other, the total amount of charge on the two conductors must remain the same. This is why each conductor acquires the same amount of charge.

In terms of mathematics, this can be represented by the equation Q = CV, where Q is the charge stored on the capacitor, C is the capacitance, and V is the voltage supplied by the battery. As the capacitance remains constant, the charge stored on each conductor will also remain constant, resulting in the same amount of charge on both conductors.

In summary, the equal charge on both conductors of a capacitor is a result of the principles of electrostatics, specifically the conservation of charge and the relationship between charge, capacitance, and voltage.
 

FAQ: Why Do Both Conductors in a Capacitor Acquire Equal Charge?

What is the formula for calculating the charge on a capacitor?

The formula for calculating the charge on a capacitor is Q = CV, where Q is the charge in coulombs, C is the capacitance in farads, and V is the voltage across the capacitor in volts.

How does the charge on a capacitor change with voltage?

The charge on a capacitor is directly proportional to the voltage across it. This means that as the voltage increases, the charge on the capacitor also increases, and vice versa.

Can the charge on a capacitor be negative?

Yes, the charge on a capacitor can be negative. This occurs when the voltage across the capacitor is negative, causing the charge to also be negative. However, the magnitude of the charge will remain the same as a positive charge with the same voltage.

What happens to the charge on a capacitor if the capacitance is increased?

If the capacitance of a capacitor is increased, the charge on the capacitor will also increase. This is because the capacitance is a measure of the capacitor's ability to store charge, so a higher capacitance means more charge can be stored.

How does the charge on a capacitor change over time?

The charge on a capacitor changes over time in a process known as charging and discharging. When a voltage is applied to a capacitor, it charges up to the voltage level. If the voltage is then removed, the capacitor will slowly discharge over time. The rate of charging and discharging is dependent on the capacitance and resistance of the circuit.

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