Potential difference across capacitors

In summary, the conversation discusses a circuit with a potential difference of 19 volts between points A and B, and the question of finding the potential difference across a three microfarad capacitor. The potential difference is determined using Kirchhoff's law and the knowledge that capacitors in series do not have equivalent voltages. The conversation also mentions difficulties with sign conventions and a request for the circuit drawing to be reattached.
  • #1
Krushnaraj Pandya
Gold Member
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Homework Statement


The figure shows part of a complete circuit. The potential at point A is greater than that of B by 19 volts what is the potential difference in volts across the three microfarad capacitor?

Homework Equations


All relevant to electric circuits

The Attempt at a Solution


From Kirchhoff's law, net potential difference across a closed loop should be 0. V(a)-(b)=19 V. Therefore, the net potential difference across given figure should be -19 V. I'm having trouble with the sign conventions related to this, since I don't know what sign to put with the batteries, otherwise since all capacitors are in series- charge across them is the same. I'd appreciate some insight.
 
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  • #2
Krushnaraj Pandya said:
The figure shows part of a complete circuit.
Which figure?:wink:
 
  • #3
The voltage would not be equivalent across capacitors in series. The voltage across all of the capacitors is the sum of the voltage across each individual one.
 
  • #4
Hi could you re-attach the circuit drawing ? It is not displaying on my iPhone
 

FAQ: Potential difference across capacitors

What is potential difference across capacitors?

Potential difference across capacitors refers to the difference in electric potential between the two plates of a capacitor. It is measured in volts (V) and represents the amount of energy stored in the capacitor.

How is potential difference across capacitors calculated?

Potential difference across capacitors can be calculated using the equation V = Q/C, where V is the potential difference, Q is the charge on the capacitor, and C is the capacitance. This equation shows that potential difference is directly proportional to charge and inversely proportional to capacitance.

Can the potential difference across capacitors be negative?

Yes, the potential difference across capacitors can be negative. This occurs when the polarity of the capacitor is reversed, meaning the positive plate becomes negative and vice versa. It is important to consider the polarity when calculating potential difference across capacitors.

How does potential difference affect the capacitance of a capacitor?

Potential difference does not directly affect the capacitance of a capacitor. However, it does affect the amount of charge that can be stored in the capacitor. As potential difference increases, the amount of charge that can be stored also increases, resulting in a higher capacitance.

What factors can influence potential difference across capacitors?

The potential difference across capacitors can be influenced by the amount of charge stored on the capacitor, the capacitance of the capacitor, and the material and size of the capacitor. Additionally, the potential difference can also be affected by the voltage of the power source connected to the capacitor.

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