0
On the contrary, capacitors ARE used in a.c. circuits.
Wiki User
∙ 10y ago
Add your answer:
Earn +20 pts
Can we use AC capacitor in surge suppression circuit DC?
A capacitor is a capacitor, no matter what circuits you use it in. There is no difference between one used in AC and one in DC, except perhaps the size that is appropriate.
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
Why a capacitor is used for amplification in common emitter circuit?
A: The ratio of emitter/collector resistance is the gain. by adding a capacitor on the emitter the AC parameters will shift as a function of frequency
Why coupling capacitor is used inelectronics circuits?
To Block DC voltages and couple AC signals through to the next circuit.
What is the purpose of a blocking capacitor?
At high frequency, capacitor can be considered as 1. Short Circuit in AC analysis. 2. Open Circuit in DC analysis. {because Xc= 1/(2*f*pi) where f= supply frequency,pi=3.14} As at high frequencies, in DC analysis, capacitor will be open circuited & can block the DC signal while AC signal is allowed to pass through.. Hence, this capacitor will act as a blocking capacitor for DC supply.
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 do you use a dc capacitor in table fans while an ac capacitor in a ceiling fan?
there is no separate capacitors for AC and DC. All capacitors are same. Electrolytic capacitors are manufactured by creating a die-electric by chemical etching or electroplating on one plate. Such capacitors when connected in AC circuit dislodges the die-electric material and thus results in short circuit between the two parallel plates of the capacitor. For AC circuits only non-electrolytic capacitors should be used. The common type is oil impregnated paper capacitor.
But in DC ciruit there is no current when capacitor is connected?
This is because when you introduce a capacitor, the circuit is no longer a DC circuit. If you're using a multimeter see if there is an AC setting to measure the current.
Capacitor inductor circuit which smooth out rectified ac voltage are known as?
filter circuits
Capacitor from emitter to ground in common emitter circuit is called?
The capacitor is called a bypass capacitor , it provides a low impedence path for AC emitter current to groun.
Why capacitor behave as open circuit against alternating current?
Capacitors store electrical charge. Imagine we have a capacitor. At time 0 seconds we connect a DC voltage across the capacitor - immediately as the voltage is connected the capacitor is at 0 volts and the maximum current (relative to the circuit resistance) flows. At this extreme the capacitor can be treated as a short circuit, so for high frequency AC volts we should treat a capacitor as being a short circuit. As time passes the current in the circuit will go down and the voltage of the capacitor will go up - this is because as the capacitor gains more charge it gains more voltage, lowering the voltage across any resistance in the circuit consequently lowering the current in the circuit. When the capacitor is virtually full no current will flow at all and the voltage across the capacitor will equal the DC source voltage. At this extreme the capacitor can be treated as an open circuit, so for low frequency AC (allowing the capacitor to fill up before the current alternates) we can treat the capacitor as being an open circuit. Technically, it is not an open/closed circuit when it comes to AC because the capacitance will results in a signal lag or lead. However, if the frequency is low/high enough the lag/lead is often negligable.
Can a capacitor be used in the Thevenin Theorem?
Sure, but it won't mean anything unless the Thevenin source is an AC source. In that case, simply determine the frequency of the source, and draw the appropriate reactance in the circuit where the capacitor belongs. If the Thevenin source is DC, then the frequency is zero, the reactance of the capacitor is infinite, and you can show it as an open circuit, i.e. not there.
