An inductor and a resistor differ primarily in how they affect current and voltage in a circuit. A resistor provides a constant opposition to current flow, converting electrical energy into heat, which results in a voltage drop proportional to the current passing through it (Ohm’s Law: V=IRV = IRV=IR). An inductor, on the other hand, opposes changes in current flow through the principle of inductance. It stores energy in a magnetic field when current flows through it and resists changes in the current by inducing a voltage opposite to the change in current (Faraday’s Law of Induction). Thus, while resistors directly dissipate energy, inductors temporarily store it and release it back into the circuit.
Inductance and resistance are different properties that describe how components behave in a circuit. Resistance, measured in ohms (Ω), quantifies a material’s opposition to the flow of electric current, resulting in energy dissipation as heat. Inductance, measured in henries (H), quantifies a component’s ability to store energy in a magnetic field as a result of current flowing through it. While resistance remains constant irrespective of the frequency of the applied current, inductance becomes more significant with increasing frequency due to its opposition to changes in current.
An inductor does not act as a resistor in the traditional sense because it does not provide a constant opposition to current flow. Instead, an inductor resists changes in the current flow. When an alternating current (AC) flows through an inductor, the inductor produces a reactance that opposes the AC, similar to how a resistor opposes direct current (DC). However, this reactance is frequency-dependent and varies with the rate of change of the current, unlike resistance which remains constant regardless of the frequency.
An inductor and a capacitor serve different functions in a circuit. An inductor stores energy in a magnetic field created by the current flowing through it, opposing changes in current. A capacitor, however, stores energy in an electric field created between its plates by an applied voltage, opposing changes in voltage. Inductors are typically used in applications where current smoothing or filtering is needed, whereas capacitors are used in applications requiring voltage smoothing, energy storage, or signal coupling/decoupling. The fundamental difference lies in their energy storage mechanism and their response to changes in current and voltage.
A current-limiting resistor and an inductor limit current differently. A current-limiting resistor provides a fixed resistance that reduces the current flow according to Ohm’s Law, dissipating excess energy as heat. It is effective for both direct current (DC) and alternating current (AC) circuits and provides immediate and constant current limitation. An inductor limits current by opposing changes in current flow due to its inductance. It does not dissipate energy as heat but instead stores it in a magnetic field. Inductors are more effective in AC circuits or circuits where current changes rapidly, providing dynamic current limiting based on the rate of current change.