By same charge I mean that same nature of charge i.e " Both positive or Both negative " . To be more specific consider two plates both of the plates are held face to face close to each other much like a capacitor but unlike a capacitor they both have positive charge so will there be a potential difference between them >?
[Physics] Will there be a potential difference between two conductors if there is same charge between them but the magnitude of charge is different
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Related Solutions
then why is there no potential difference between the two capacitors
It's not quite clear what you mean here but do understand that charged capacitors are electrically neutral.
When a capacitor is "charged", it is not electrically charged, it is energy charged in the same sense as when we say a battery is charged.
There is nothing mysterious about two series connected circuit elements having different voltage drops. Think of two series connected resistors with different resistor values.
I would have thought that as plate B is positively charged and plate C is negatively charged, there would be a potential difference between the two
You're forgetting something fundamental: The plates B and C along with the wire that connects them are conductors. But, for an ideal conductor, charge distributes itself so that there is no (static) potential difference across the conductor.
The voltage between the bottom plate of C1 and the top plate of C2 is zero precisely because a conductor connects the two plates.
Why are potential differences equal across two capacitors in series, but charge on each capacitor is not?
This is based on a false premise. There is no rule that says that "potential differences are equal across two capacitors in series".
In a parallel combination of capacitors potential difference across each capacitor is same but each capacitor will store different charge. Why is this true?
In a lumped circuit model, any two devices in parallel must have the same potential across them. This is because of Kirchoff's voltage law (KVL) which says that the net potential drop around any loop in a planar circuit is zero. To put it in more basic terms, if the potential at point 'A' is $V_a$ and the potential at point 'B' is $V_b$, then the potential difference between points A and B is $V_a - V_b$ no matter what path you take through the circuit between those points.
As arvindpujari's answer points out, since the potential differences are equal across the two parallel capacitors, this means that if the capacitance values aren't equal then they must have different charges since a linear capacitor is defined by the equation $V=Q/C$.
Also, in series, why are Potential difference across each capacitor different, while charge is the same?
Imagine you start with two capacitors in series with no charge ($V=0$). Then start driving a current through them. The same current will flow through both capacitors (that's what it means for two elements to be in series), so the same charge will accumulate on each capacitor's plates.
Since they have equal charge, if the capacitance values are not the same, then the potentials must also not be the same.
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Best Answer
If by magnitude difference you mean Plate A has a charge of +1 and plate B has a charge of +9, then there will be a potential difference. If by magnitude difference you mean Plate A has a charge of +1 and plate B has a charge of +1, then there won't be a potential difference.