Capacitor and inductor are two electrical components used in circuit design. Both of them belong to passive elements category, which draw energy from the circuit, store, and then release. Both capacitor and inductor are widely used in AC (alternative current) and signal filtering applications.
Capacitor
Capacitor is made of two conductors separated by an insulating dielectric. When a potential difference is provided to these two conductors, an electric field is created and electric charges are stored. Once the potential difference is being removed and two conductors are connected, a current (stored charges) flows to neutralize that potential difference and electric field. The rate of discharge gets reduced with time and this is known as the capacitor discharging curve.
In analysis, capacitor is considered as an insulator for DC (direct current) and conducting element for AC (alternating currents). Therefore, it is used as a DC blocking element in many circuit designs. Capacitance of a capacitor is known as the capability to store electric charges, and it is measured in the unit called Farad (F). However in practical circuits, capacitors are available in the ranges of micro Farads (µF) to pico Farads (pF).
Inductor
Inductor is simply a coil and it stores energy as a magnetic field when an electric current passing through it. Inductance is a measure of an inductor’s capability to store energy. Inductance is measured in unit Henry (H). When an alternative current is passing through an inductor, a voltage across the device is observable due to changing magnetic field.
Unlike capacitors, inductors act as conductors for DC, and the voltage drop on the element is almost zero, as there is no changing magnetic field. Transformers are made of coupled pair of inductors.
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What is the difference between Capacitor and Inductor? 1. Capacitor stores an electric field, whereas inductor stores a magnetic field. 2. Capacitor is open circuit for DC, and inductor is short circuit for DC. 3. In an AC circuit, for capacitor, voltage ‘lags’ current, whereas for inductor, current ‘lags’ voltage. 4. Energy stored in a capacitor is calculated in terms of voltage (1/2 x CV2), and this is done in terms of current for inductor (1/2 x LI2)
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