The Transfer Function That Settled at 5, Not 20
A transfer-function numerator is not automatically the steady-state gain. Diagnose why H(s) = 20/(s+4) gives a unit-step final value of 5.
Topic: Linear Systems
The RLC Circuit That Peaked Instead of Filtering
An inductor and capacitor do not always add opposition. At series resonance, their reactances cancel and current can reach its maximum value.
The Capacitor That Drew Too Much Current
A capacitor is open-circuit at DC steady state, but that does not mean startup current is zero. Diagnose a 10 mA switch-on current in an RC circuit.