# Looking for capacitive reactance but missing "C"

1. Jul 22, 2014

### tessie0407

1. Current and voltage graphs are shown for a capacitor circuit with ƒ=1000Hz.
What is the capacitive reactance Xc?

2. I know the equation is Xc= 1/2∏ƒC to solve for capacitive reactance but where do I find C? All of our in class examples had C and ƒ given.

3. The attempt at a solution

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2. Jul 22, 2014

### Staff: Mentor

That formula is not correct. You need a pair of brackets to set it right or you'll never get the right answer!

What would be the equation for current if you connect that capacitance C to an AC voltage source V volts?

3. Jul 22, 2014

### SammyS

Staff Emeritus

Get the reactance from the graph.

What are peak voltage & peak current?

4. Jul 22, 2014

### tessie0407

The only other thing I can think to do is rearrange ΔVc= I*Xc

Xc= ΔVc/I
Xc= 10V/10x10^-2 A which gives me 100Ω

5. Jul 23, 2014

### Staff: Mentor

10V looks right for the voltage. But that's not the right way to write 10mA.