Why Is There a '2' in the Capacitor Force Equation?

In summary, parallel plates capacitance is the measure of the ability of two parallel plates to store electric charge when a voltage is applied between them. It is calculated using the formula C = ε0A/d, where C is the capacitance, ε0 is the permittivity of free space, A is the area of the plates, and d is the distance between the plates. The distance between the plates plays a crucial role in determining the strength of the electric field between the plates and thus affects the capacitance. When the distance between the plates is decreased, the capacitance increases because the electric field becomes stronger. The material between the plates, known as the dielectric material, also affects capacitance by increasing it due to its higher perm
  • #1
AgPIper
7
0
A parallel plate capacitor has charge Q and plates of area A. What force acts on one plate to attract it toward the other plate?

It's F = Q^2 / (2*8.854e-12*A) ... something to do with the electric field divided in 2? Wondering why there's a 2 in the denominator... thanks :)
 
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  • #2
To find the force that one plate exerts on the other, first find the field created by the charge on that plate. That's where the 2 will come in.
 
  • #3


The force acting on one plate of a parallel plate capacitor is known as the electrostatic force and it is given by the formula F = Q^2 / (2*8.854e-12*A). This force is responsible for attracting the plates towards each other. The 2 in the denominator represents the distance between the plates, which is divided by 2 in the formula. This is because the electric field between the plates is divided in half due to the fact that the electric field lines originate from one plate and terminate on the other plate. Therefore, the strength of the electric field is also divided by 2, resulting in the 2 in the denominator. I hope this helps to clarify any confusion.
 

FAQ: Why Is There a '2' in the Capacitor Force Equation?

What is the definition of parallel plates capacitance?

Parallel plates capacitance is the measure of the ability of two parallel plates to store electric charge when a voltage is applied between them. It is determined by the distance between the plates, the area of the plates, and the material between the plates.

How is the capacitance of parallel plates calculated?

The capacitance of parallel plates can be calculated using the formula C = ε0A/d, where C is the capacitance, ε0 is the permittivity of free space, A is the area of the plates, and d is the distance between the plates.

What is the significance of the distance between the plates in parallel plates capacitance?

The distance between the plates plays a crucial role in parallel plates capacitance because it determines the strength of the electric field between the plates. A larger distance results in a weaker electric field and a lower capacitance, while a smaller distance results in a stronger electric field and a higher capacitance.

What happens to the capacitance when the distance between the plates is decreased?

When the distance between the plates is decreased, the capacitance increases because the electric field between the plates becomes stronger. This means that the plates can store more charge for the same applied voltage.

How does the material between the plates affect parallel plates capacitance?

The material between the plates, also known as the dielectric material, affects parallel plates capacitance by increasing the capacitance compared to when there is air or vacuum between the plates. This is because the dielectric material has a higher permittivity, which allows it to store more electric charge.

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