# Finding voltage and current expressions (capacitance)

1. Jul 12, 2012

### appleraja

1. The problem statement, all variables and given/known data

The charge on a 2-microfarad capacitor is given by q(t)=10^-6 * sin(10^5*t) C find the dexpression for the voltage and current?

2. Relevant equations

3. The attempt at a solution
the answer is v(t)=0.5sin(10^5t) , i(t)=0.1cos(10^5t) i dont get how they found the answer

2. Jul 12, 2012

### grzz

Note that q = Cv and i = $\frac{dq}{dt}$.

3. Jul 12, 2012

### appleraja

what im confused is when they say, charge is microfarad does that mean q=2x10^-6 or is the capacitor 2 microfarad meaning c=2x10^-6

4. Jul 13, 2012

### Staff: Mentor

Capacitance is given in farads (microfarads in this case), while charge is given in coulombs (C).