0
When you apply DC directly to a capacitor, it charges to the value of the DC potential, and then there is (nearly1) zero current flow through the capacitor. If the capacitance is large enough, though, and the DC source has a low enough impedance, the current flow can be quite substantial, damaging things.
The reason the equilibrium current is zero is that a capacitor resists a change in voltage, proportional to current and inversely proportional to capacitance...
dv/dt = i/c
... which makes the capacitor essentially a high pass filter, and a DC blocker.
1 The equilibrium current is "nearly" zero because, in our non-ideal world, every capacitor has some leakage current. Practically, the current is zero - from a purist perspective, it is not.
What else can I help you with?
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.
Can a non polarized capacitor be connected to a direct current circuit?
Yes, you can connect a polarized capacitor to a direct current. Make sure you get your polarization is correct.A non polarized capacitor can be connected in a DC circuit as well. "Non Polarized" just means it does not matter which side of the capacitor is positive. If you attempt to connect a polarized capacitor in a DC circuit backwards, you will know when the capacitor explodes.
What will happen if two terminals of capacitor are shorted?
When the terminals of a capacitor are connected together, the capacitor will discharge, returning to a zero potential state. Capacitors resist voltage change, meaning that if the capacitor is in a circuit that has zero voltage potential, the capacitor will eventually achieve zero potential. If the capacitor is in a circuit that has a 5 volt potential, the capacitor will seek and attempt to maintain that 5 volt potential (provided that the capacitor is rated at 5 volts or more). In an AC circuit, the capacitor will tend to smooth out the sin wave of the current, resisting change in both directions. In a DC power supply circuit, a capacitor will tend to reduce the voltage "ripple", and if the circuit is designed properly, will provide a smooth DC voltage. Shorting the terminals of a capacitor is effectively what often happens in many circuits; it's not a problem.
What is the function of mylar capacitor?
In electronic circuits a capacitor is used to pass AC and block DC.
What devices can be used to block DC and pass AC?
simple capacitor can do this job (to block dc and pass ac).
What is dc link capacitor?
when the DC current flows through the capacitor .the leakage of the charges is in capacitor called Dc leakage capacitor .
What capacitor blocks either ac or DC?
Always DC.
What happens when a capacitor connected across a battery for a long time?
For a long time, The capacitor will be charged to the voltage of the DC battery, the positive side of the capacitor touching the positive terminal of the battery. Not much DC current will conduct, except for some tiny leakage current due to imperfection of the cap. The battery will be drained eventually.
What happens when a capacitor is connected to a dc supply?
is it ? are you sure ? but i know so many circuit where capacitor is connected with ac supply . still , if u connected a capacitor to dc supply , then : 1. if it is in SERIES with the dc supply , it will block all the dc current as capacitor provides infinite resistance to dc current . application : where u want to block dc current.(simple high pass filter) 2. if it is in PARALLEL with the dc supply , it will not block dc current , but if any ac current comes out from the supply , the ac current will go through the capacitor , as capacitor provides small resistance to ac current. application : a) where u want to block ac current.(simple low pass filter) b) to filter the noise (ac components) of dc supply.
What happens if you put dc on ac device?
the answer is Rectifier. it converts ac voltage into dc which can apply to the dc device
Can capacitor work in dc?
Yes.
What happens to current flow in a capacitive when the DC voltage across the capacitor is approximately equal to the source voltage?
As long as you don't exceed the breakdown voltage of the capacitor ... which is marked right on it ... DC voltage on it produces NO current flow through it. Only AC 'appears' to flow through a capacitor, and even that appearance is bogus when you really get down to it.
What happens to the output voltage of a rectifier if the capacitor becomes very leaky?
A leaky capacitor will act like a load therefore decreasing the DC and increasing ripple eventually the capacitor it will self destruct because of heating probaly taking out the rectifiers as well.
A resistor and a capacitor are connected in parallel across a 120 v dc source determine the voltages across the resistor and the capacitor?
Since they're connected in parallel directly across the source, the voltages across both componentsare equal, and are equal to the source, i.e. 120 v DC.
How do you charge a 18 volt dc capacitor?
You charge all capacitors the same way - you apply a current across them. The equation is dv/dt = i/c.
When DC power is first applied to an uncharged capacitor it appears as a?
When DC power is first applied to an uncharged capacitor it appears as a short circuit.
Will a capacitor lower voltage?
A: As soon as a DC voltage is applied the capacitor is a short or no voltage
