Question 3-28C1

When a diode junction is forward biased, a voltage is applied across it in the direction that allows current to flow easily. This applied voltage overcomes the diode's internal potential barrier (depletion region), effectively narrowing it and causing the diode's resistance to drop significantly. **C) It is a low impedance.** This is correct because a low resistance path allows a large current to flow for a given voltage. The diode offers minimal opposition to the current, which is the definition of low impedance. **A) It is a high impedance.** This is incorrect. A high impedance implies significant opposition to current flow, which describes a reverse-biased diode or an open circuit, not a forward-biased one. **B) It conducts very little current.** This is incorrect. Due to its low impedance state, a forward-biased diode is designed to conduct substantial current once its forward voltage threshold is met. **D) It is an open circuit.** This is incorrect. An open circuit has infinite impedance and conducts no current. A forward-biased diode specifically provides a path for current flow.