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A capacitor allows AC (to pass through) because capacitors resist a change in voltage. The equation of a capacitor is ...
dv/dt = i/c
... meaning that the rate of change of voltage in volts per second is equal to current in amperes divided by capacitance in farads.
The simplified explanation (using more words) is that, when a DC voltage is applied to a capacitor, it ultimately charges to that DC voltage and, at equilibirum, presents a large impedance, but when an AC voltage or step change is applied to a capacitor, it initially presents a low impedance, allowing the AC or step to pass through.
If you have an AC signal riding on top of DC, the capacitor will stabilize to an output DC offset of zero while passing the AC. This is useful, for instance, when coupling an AC signal to the input of a transistor amplifier, while allowing the base bias circuit to keep the transistor in its intended bias state, while at the same time allowing the AC signal to pass through into the transistor and be amplified.
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∙ 9y ago
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When capacitor is having an insulation how is it allowing ac current?
Capacitor does not allow any current through it.By the changing of electric field across the plates it is usually assumed that capacitor allow ac through it.Is it???
Did capacitor allow change in current?
capacitors allow ac current to flow.
Does a Cpacitor allow ac to pass through it?
no capacitor does not allow ac component .if allow then inductor allow dc component .
Why ac pass by capacitor as it has infinite resistance?
ac passes by repeatedly charging and discharging the capacitor. when you study ac circuit analysis, you will find out about impedance and reactance, which will allow you to compute how ac behaves in capacitors and inductors.
Why you using DC power supply for capacitor?
Because it does not allow ac to pass through it...
Why a capacitor does not accept AC?
A capacitor conducts AC but do not conduct DC because it is meant to store charge.
Why capacitor in transistor amplifier circuit at input?
Because capacitor not allow to pass dc voltage,but capacitor allow ac voltage and signal.Purpose is to block dc voltage.That is coupling condenser.
Do ac capacitor have polarity?
no
Why don't capacitors allow DC current to pass?
A capacitor allows AC (to pass through) because capacitors resist a change in voltage.. The capacitor need change resist in Input signal
How does capacitor discharge while ac supply is on?
For part of the AC voltage wave, the capacitor will be above the source voltage, and will discharge until the AC voltage wave increases above the capacitor's stored voltage.
What is ac ground?
If a circuit is grounded through a capacitor it is referred to as AC ground because ac signal can pass through the capacitor DC level is blocked
Can capacitor store charge from ac source?
Yes. A capacitor stores charge from any source, including AC.The difference between DC and AC, however, is that the capacitor will be constantly changing in charge, in step with the AC. Due to the nature of the capacitor, the current through the capacitor will lead the voltage by some amount, depending on capacitance and resistance. {In the ideal case of a perfect capacitor, conductors, and AC power source, the current will lead the voltage by 90 degrees phase angle.}This is called capacitive reactance.Another way for a capacitor to store charge from an AC source, of course, is to place a rectifier diode in front of the capacitor. This, then, becomes an AC to DC converter.
