1 . 1 . Use the Loop Rule to write an equation relating the different potential differences in a series loop of a resistor R

$1.$ Use the Loop Rule to write an equation relating the different potential differences in a series loop of a resistor R$,$ a capacitor C and a battery epsi as shown. Hint use Ohm$\text{'}$s law to get the potential difference across the resistor and the definition of capacitance to get the potential difference across the capacitor.

How many different variables are there?

$2.$ To reduce variables, substitute for the current I the definition of current I $=$ dq$/$dt $.$

What type of equation is this?

$3.$ Solve for the charge q as a function of time.

Describe how the charge on the capacitor in an RC circuit depends on time.

$4.$ Differentiate the result q with respect to time to get the current as a function of time.

Describe how the charge on the capacitor in an RC circuit depends on time.

What does the constant RC represent?

R I b + b - S +-