Why capacitive reactance reduces inductive reactance (by intuition/physically not mathematically)?

Sensacell

Joined Jun 19, 2012
3,785
The coil and capacitor both have the ability to store energy, but in opposite, and totally complimentary ways.
A capacitor stores energy in the form of an electrostatic field.
An inductor stores energy in the form of a magnetic field.

In an LC parallel resonant circuit, the energy "sloshes" back and forth between the L and the C, being transformed continuously between magnetic energy and electrostatic energy, until losses or transfer to the external world removes the energy.

When the voltage is at it's peak, the current is zero- this is when the energy is entirely electrostatic - inside the capacitor.
When the voltage is zero, the current is at it's peak, and the energy is entirely magnetic - inside the inductor.

Think of inductors and capacitors as being the perfect opposite compliments to each other, with perfectly inverse properties - everything a coil is, a capacitor is not- and vice versa- it's poetry.
 

WBahn

Joined Mar 31, 2012
32,848
However coil doesn't like change in current, so it creates a voltage whose polarity is in the direction of current flow.
The voltage that is produced by the coil has nothing to do with the polarity of the current flow, it has to due with the polarity of the CHANGE in current flow.

An often better way to think about it is that in order to change the current in an inductor, you must apply a voltage. If your symbolic current and voltage are defined per the passive sign convention, then a positive voltage will result in the current becoming more positive (or less negative), while if it is negative, it will become less positive (or more negative).
 
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