# Current through capacitor

1. Aug 10, 2009

### circuitaki

calculate the current through the capacitor 100mF in response of voltase 20-

2. Aug 10, 2009

### queenofbabes

3. Aug 10, 2009

### circuitaki

I want to find out the i if v across capacitor is -20v

I know the formula is i = C dv/ dt

but here I have no t

only capacitance and voltage

Last edited: Aug 10, 2009
4. Aug 10, 2009

### diazona

It's not a t. It's a derivative with respect to time. dv/dt is the rate of change of voltage with respect to time. Can you find that?

5. Aug 11, 2009

### circuitaki

hi dear,

if t is the rate of change of time then how can i drive it kindly guide

6. Aug 11, 2009

### Redbelly98

Staff Emeritus
With the given information, you can only get the charge on the capacitor. Calculating i is impossible without more information.

I suggest you look carefully at the problem statement again, is there any other information? Or a figure?

7. Aug 11, 2009

### circuitaki

hi dear,

Kindly check that we have voltage and capacittance as

v= -20 v

and

capacitace

5 mF

8. Aug 11, 2009

### Redbelly98

Staff Emeritus
Maybe this question is easier than we are making it out to be.

If v = a constant -20V, then

dv/dt = ____?​