Firstorder Circuits Are Circuits That Contain Only One Energy Storage Element(Capacitor or Inductor), and That Can Therefore Be Described Using Only a Firstorder Differential Equation. the Two Possible Types of First-Order Circuitsare: Rc (Resistor and Capacitor) Rl (Resistor and Inductor) Rland Rc Circuits Is a Term We Will Be Using to Describe a Circuit That Haseither A) Resistors and Inductors (Rl), or B) Resistors and Capacitors (Rc).