Capacitance of parallel plates as a function of distance

[v_pino]

Capacitance= (permitivity x Area of overlap)/ distance between two plates

Why is capacitance inversely proportional to the distance between two plates?

I understand that C=Q/V. So capacitance is the amount of charge it takes to change the potential difference between the two plates by 1 volt. And another definition of capacitance is the ability to store charge.

 

[Hootenanny]

Hyperphysics has a good explanation http://hyperphysics.phy-astr.gsu.edu/hbase/electric/pplate.html#c2".

 

[astrokreng]

As you have correctly stated, capacitance is defined as the ratio of charge (Q) to voltage (V). In the case of parallel plates, the capacitance is determined by the geometry of the plates and the distance between them.

The inverse relationship between capacitance and distance can be understood by considering the electric field between the plates. As the distance between the plates decreases, the electric field becomes stronger. This means that a smaller amount of charge is needed to produce the same voltage difference between the plates. In other words, the capacitance decreases as the distance decreases.

On the other hand, when the distance between the plates increases, the electric field becomes weaker. This requires a larger amount of charge to produce the same voltage difference, resulting in an increase in capacitance.

Therefore, we can say that capacitance is inversely proportional to the distance between two plates because the electric field between the plates is directly affected by the distance. A smaller distance means a stronger electric field, requiring less charge and resulting in a lower capacitance.

This relationship is important in understanding the behavior of capacitors in electronic circuits. By controlling the distance between the plates, we can manipulate the capacitance and thus control the flow of charge within the circuit.