Conceptual Question-Capacitance

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A 2.50 μF capacitor connected to a 9.30 V power supply retains its capacitance even when the voltage is increased by 3.00 V. The confusion arises from the relationship described by the equation Q=ΔV*C, which indicates that while charge (Q) increases with voltage (V), capacitance (C) remains constant. Capacitance is determined solely by the capacitor's material and geometry, not by voltage or charge. Therefore, increasing the voltage does not affect the capacitance value. The key takeaway is that capacitance is an intrinsic property of the capacitor.
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Homework Statement


We start with a 2.50 μF capacitor connected to a power supply set to a voltage of 9.30 V. Then we increase the voltage on the power supply by 3.00 V. Now what is its capacitance?

Homework Equations


Q=ΔV*C

The Attempt at a Solution


The answer is 2.5 μF still, but WHY doesn't the capacitance change when the voltage changes?
 
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PlatoDescartes said:
The answer is 2.5 μF still, but WHY doesn't the capacitance change when the voltage changes?
Why do you think it should? If you had a 10 ohm resistor across the power supply would you expect it to become 11 ohms if you increased the voltage?
 
phinds said:
Why do you think it should? If you had a 10 ohm resistor across the power supply would you expect it to become 11 ohms if you increased the voltage?
According to the equation Q=VC, if voltage increases, capacitance should too... I'm missing something here... I apologize!
 
PlatoDescartes said:
According to the equation Q=VC, if voltage increases, capacitance should too... I'm missing something here... I apologize!
Capacitance is not dependent on voltage nor charge though, only material/geometry. Which is why it doesn't change.
 
Q is the charge.

If you increase the voltage (V), the charge increases but the capacitance (C) stays constant.
 

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