5.00 N 3.00 V 8.00 V 3.00 N 4.00 V 6.00 µF 5.00 N I= 0

The circuit in the figure below has been connected for a long time. Let R1 = 8.60 Ω and R2 = 4.20 Ω. (a) What is the potential difference across the capacitor?(b) If the battery is disconnected from the circuit, over what time interval does the capacitor discharge to one-tenth its initial voltage?

You connect an initially uncharged 6.40 mF capacitor in series with a 5.00 MΩ resistor and a battery with emf 12.0 V. After letting the capacitor charge for 51.0 s, you disconnect it from this circuit and connect it in series to an open switch and a 6.00 MΩ resistor. Find the charge on the capacitor (a) when you disconnect it from the first circuit and (b) 70.0 s after you close the switch in the second circuit.

A heart pacemaker fires 67 times a minute. Each time it fires, a 35.0 nF capacitor is charged by a battery in series with a resistor to 0.682 of its full voltage. What is the resistance?