Capacitance

Question 1

What is a capacitor

Answer 1

2 metal plates separated by an insulator, such as paper or air. As electrons flow from the negative terminal of a power supply to the capacitor, they become stuck at one plate as they cant go past it. Electrons on the other plate are attracted to the negative terminal of the power supply, leaving the plate and moving around the circuit, becoming positive. Eventually the capacitor becomes fully charged and has a potential difference equal to the emf of the power supplier.

Question 2

Capacitance in circuits

Answer 2

1/c in series, c in parallel

Question 3

Equation for discharging

Answer 3

x=x0e^-t/cr

Question 4

charging equation

Answer 4

x=x0(1-e^-t/cr)