Which of the following expressions gives the capacitance for a capacitor in a circuit in which the only factors known are a) the current through the circuit, b) the resistance of the circuit, and c) the charge that has accumulated on the capacitor?

A parallel plate capacitor with no dielectric has capacitance . The distance between the capacitor plates is halved. What is the new capacitance?

An RC circuit is connected to a power supply. If the resistance of the resistor is and the capacitance is , how long will it take for this capacitor to become fully charged?