Conceptual Question-Capacitance

[PlatoDescartes]

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?

 

[phinds]

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?

 

[PlatoDescartes]

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]

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.

 

[magoo]

Q is the charge.

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