In this chapter we analyze simple electric circuits that contain devices such as batteries, resistors, and capacitors in various combinations. We begin by introducing steady-state electric circuits
and the concept of a constant rate of flow of electric charges, known as direct current (dc)
. We also introduce Kirchhoff’s two rules
, which are used to simplify and analyze more complicated circuits. Finally, we consider circuits containing resistors and capacitors, in which currents can vary with time.