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'when frequency is increased why capacitance increases in a capacitor'?
Wiki User
∙ 9y ago
Answer:
Capacitance is unaffected by frequency; it does not change.
Details:
Capacitance is unaffected by frequency. In a capacitor, what increases with Frequency is Admittance (analogus to Conductance) .
The capacitive Reactance is inversely proportional to Frequency. Therefore, when Frequency is increased, current flow may increase.
Wiki User
∙ 9y ago
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Why does capacitance increase when the distance between the plates of a capacitor is increased?
you have it reversed. capacitance increases with decrease in distance of plates.
The capacitive reactance of a capacitor increase as?
The capacitive reactance of a capacitor increases as the frequency decreases.
Does increasing the plate area of a capacitor increases the capacitance?
Yes. Increasing the plate area of a capacitor increases the capacitance. The equation of a simple plate capacitor is ...C = ere0(A/D)... where C is capacitance, er is dielectric constant (about 1, for a vacuum), e0 is electric constant (about 8.854 x 10-12 F m-1), A is area of overlap, and D is distance between the plates. (This is only a good estimate if D is small in comparison to A.) Looking at this, you can see that capacitance is proportional to plate area.
What is the effect on charging and discharging times if the capacitance is increased?
The charging and discharge time increases. R*C=T
What is amplifier roll off?
A practical amplifier will contain several components of a "shunt" capacitance inherent in the transistor and physical wiring of the amplifier circuit. As the frequency of the input signal increases, the reactance of these shunt-capacitances will decrease until, at a frequency determined by the value of the shunt-capacitance and the circuit impedance, signal attenuation begins to take place. Thus the shunt capacitances limit the high-frequency response of the amplifier (note that the transistor itself also has inherent limits to it's high frequency amplifying capability). In the case of operational amplifiers, many operational amplifiers are internally compensated by a small capacitor (e.g. about 30pf for a 741). The internal frequency compensation capacitor prevents the operational amplifier from oscillating with resistive feedback.
Why does capacitance increase when the distance between the plates of a capacitor is increased?
you have it reversed. capacitance increases with decrease in distance of plates.
How capacitor behave in alternating current?
Capacitors have an equivalent reactance of 1/jwC (ohms) where w is the angular frequency of the AC signal and C is the capacitance. As the frequency of the signal across the capacitor increases, the capacitor reactance approaches 0 (capacitor acts like a short circuit). As the frequency of the signal across the capacitor decreases, the capacitor reactance approaches infinity (capacitor acts like an open circuit). So, if you have a high frequency signal (like a step input) the capacitor will momentarily act like a short.
Does the capacitor's opposition to alternating current increase or decrease as the frequency of the current increases?
Capacitive reactance (expressed in ohms) is inversely-proportional to the supply frequency, so it will decrease when the frequency increases. The following equation applies:XC = 1/(2 pi f C)where:XC = capacitive reactance, in ohmsf = frequency, in hertzC = capacitance, in farads
The capacitive reactance of a capacitor increase as?
The capacitive reactance of a capacitor increases as the frequency decreases.
The charge on a capacitor increases by 16 C when the voltage across it increases from 82 V to 121 V What is the capacitance of the capacitor?
Q = CV, Q is charge, C is capacitance, V is voltage. C= Q/V = dQ/dV since it is linear function = 0.41F
What is the effect of inserting a dielectric other than air on vacuum between the plates of a capacitor?
Capacitance definitely increases
Does increasing the plate area of a capacitor increases the capacitance?
Yes. Increasing the plate area of a capacitor increases the capacitance. The equation of a simple plate capacitor is ...C = ere0(A/D)... where C is capacitance, er is dielectric constant (about 1, for a vacuum), e0 is electric constant (about 8.854 x 10-12 F m-1), A is area of overlap, and D is distance between the plates. (This is only a good estimate if D is small in comparison to A.) Looking at this, you can see that capacitance is proportional to plate area.
What is the effect of inserting a dielectric other than air vacuum between the plates of a capacitor?
It usually increases the value of the capacitance.
Why would there be a gain when you add the emitter capacitor to a circuit board?
A capacitor has lower resistance (impedance) as frequency increases. Adding an emitter capacitor effectively lowers the emitter resistance as frequency increases. Since gain in a typical common emitter amplifier is collector resitance divided by emitter resistance, this decrease in emitter resistance will increase gain as frequency increases.
How introduction of a die-electric increases the capacitance of the capacitor?
By connecting a capacitor in series the total dielectric thickness between the positive and negative terminals of the source, since you double dielectric thickness has effectively doubled, the total capacitance is one half of either capacitors.
What happens to the frequency of a wave when the energy is increased?
Frequency increases proportionally. E=hf
What is the effect on charging and discharging times if the capacitance is increased?
The charging and discharge time increases. R*C=T
