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When the frequency of an applied voltage is increased the capacitive reactance of a circuit will?
Wiki User
∙ 12y ago
Since capacitive reactance is inversely-proportional to the supply frequency, as the frequency is increased, the reactance will decrease.
Wiki User
∙ 12y ago
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What is a serial resonant circuit?
A series resonant circuit is one in which the inductive and capacitive reactance are equal in magnitude. Since the signs of the vectors of their reactance are opposite, they cancel and so leave only the resistance of the series circuit at the resonant frequency. Because reactance of a capacitor is inversely related to frequency, and the reactance of an inductor is directly related to frequency, this happens at a particular frequency dependent on the values of capacitance and inductance. You see, when you apply a sine wave to an inductor, the current lags behind the voltage by 90 degrees. Or you may look at it as the voltage leading the current by 90 degrees. But when a sine wave is applied to a capacitor, the reverse is true. Current leads voltage by 90 degrees. Or voltage lags behind current by 90 degrees. Put a capacitor and inductor in series and input a sine wave of current at the frequency at which both have the same amount of reactance. Current is equal in magnitude and phase everywhere in a series circuit. Voltage dropped across the inductor is 90 degrees ahead of the current, while voltage dropped across the capacitor is 90 degrees behind the current. This puts the voltage drops 180 degrees out of phase with each other. Because the applied frequency is the one at which the reactance of each component is equal in magnitude, the voltage drops are also equal in magnitude so they sum to zero volts. Zero volts at any current is zero ohms (Ohm's law, R = E/I). In the real world, both parts have resistance or a series resistor may be part of the design. But the end result is that impedance of the series circuit is lowest at the resonant frequency.
How are FM signal generated?
There are several methods for generating FM signals but they all basically involve an oscillator with an electrically adjustable frequency. This type of oscillator uses an input voltage to affect the frequency of its output. For example, when the applied voltage increases, the oscillator output frequency increases and when the applied voltage decreases, the oscillator output frequency decreases as well. If no voltage is applied to the oscillator its output will be a signal at its centre frequency. The amount of frequency variations is deviated around the oscillators' centre frequency.
In a purely resistive AC circuit where 240V is applied across a 10-ohm resistor the amperage is?
Since Ohm's law states that current is voltage divided by resistance, if you place 240 volts across 10 ohms, you will get 24 amperes. This is true for AC and DC. It is also true for inductive or capacitive circuits, except that the calculation of apparent resistance (reactance) and phase angle of current to voltage becomes more complex.
What is electrical impedence?
Electrical impedance is the total opposition to current flow. It includes both a resistive, or DC component and a reactive, or frequency-dependant component. Impedance is the same as resistance if the applied voltage is DC. For AC voltage, the reactive components opposition to current flow changes with frequency, so impedance is typically specified at a particular frequency.
Why do you have variation in leakage reactance of induction motor?
leakage reactance in induction motor depends on the reluctance of the path in which the leakage flux is establishing. with the increase in stator current the leakage flux also increases but it cannot maintain linear relationship because of saturation of the leakage flux path, even though current is increasing the flux will not increase and it'll be constant after saturation. this leakage flux links with the stator winding and induces emf which will be opposite to the supply voltage causes drop in applied voltage , the drop in the applied voltage is represented with the leakage reactance. as flux is responsible for the induction of emf , the increase in current does not increase flux after saturation and therefore emf also doesnot increase so the leakage reactance is not constant throughout the machine operation...
What is difference in resistance and reactance?
Resistance is a concept used for DC. the current through a resistance is in phase with the applied voltage Reactance is used for AC the current through a inductive reactance lags the applied voltage by 90 degrees. the current through capacitive reactance leads the applied voltage by 90 degrees. the net reactance is the difference between inductive and capacitive reactance
What is the reactance of a 25 uf capacitor when the applied frequency is 400 hz?
Reactance is -1/2 pi F C so a 25 uF capacitor at 400 Hz would have a reactance of about -15.9 ohms. The negative sign indicates that capacitive reactance is leading, with current leading voltage.AnswerI would take issue with the previous answer that capacitive reactance is expressed as a negative value, or that it is 'leading'. Reactance is not a vector quantity, so it neither leads nor lags anything. In a (theoretically) purely capacitive circuit, it is the load current that leads the supply voltage. However, when using complex notation, capacitive reactance is expressed as -j 15.9 ohms, where 'j' is called an 'operator' -but even this does not mean that the reactance is 'leading', as it defines reactance in terms of a current phasor -in other words, the '-j' refers to the relative position of current to voltage, not reactance to impedance.
What is the difference between capacitive reactance and capacitance?
Capacitance is a physical characteristic of a pair of conductors, dependent upon the distance between them, the opposing cross-sectional areas of those conductors, and the nature of the dielectric between them, and is measured in farads.Capacitive reactance is the opposition to the flow of current of a circuit, determined by that circuit's capacitance and the frequency of the a.c. supply applied to that circuit, and is measured in ohms.
What is difference between resistance and reactance while both are measured in ohms?
Resistance is constant no matter the frequency applied. Reactance varies depending on the frequency of the power applied to it.
What is the impedance of a series R-L-C circuit?
the net oppostion offered by the rlc circuit for the ac current to pass through it is called the impedance of rlc circuitAnswerThe impedance of an RLC circuit is the vector sum of the circuit's resistance, inductive reactance, and capacitive reactance, expressed in ohms.
What is the difference between 50 Hertz and 61 Hertz?
Frequency is determined by the supply voltage, not by the load. However, for reactive loads (inductors or capacitors), the reactance will vary according to the frequency applied.
What is a serial resonant circuit?
A series resonant circuit is one in which the inductive and capacitive reactance are equal in magnitude. Since the signs of the vectors of their reactance are opposite, they cancel and so leave only the resistance of the series circuit at the resonant frequency. Because reactance of a capacitor is inversely related to frequency, and the reactance of an inductor is directly related to frequency, this happens at a particular frequency dependent on the values of capacitance and inductance. You see, when you apply a sine wave to an inductor, the current lags behind the voltage by 90 degrees. Or you may look at it as the voltage leading the current by 90 degrees. But when a sine wave is applied to a capacitor, the reverse is true. Current leads voltage by 90 degrees. Or voltage lags behind current by 90 degrees. Put a capacitor and inductor in series and input a sine wave of current at the frequency at which both have the same amount of reactance. Current is equal in magnitude and phase everywhere in a series circuit. Voltage dropped across the inductor is 90 degrees ahead of the current, while voltage dropped across the capacitor is 90 degrees behind the current. This puts the voltage drops 180 degrees out of phase with each other. Because the applied frequency is the one at which the reactance of each component is equal in magnitude, the voltage drops are also equal in magnitude so they sum to zero volts. Zero volts at any current is zero ohms (Ohm's law, R = E/I). In the real world, both parts have resistance or a series resistor may be part of the design. But the end result is that impedance of the series circuit is lowest at the resonant frequency.
What is the ohm rating of a 10v 330uf electrolytic capacitor?
Capacitive reactance is -1 / (2 pi f C), so the reactance of a 330 µf capacitor at 60 hz is -8 ohms. (The negative sign simply means that the current will lead the voltage.) However, an electrolytic capacitor is not designed for operation on AC, as it can only have voltage applied to it in one direction only. The equation still holds, however.
What is the applied voltage to a resistive capacitive circuit?
this is the amount of voltage a circuit can hold.
Can ac pass through capacitor?
AC can pass through a capacitor. The higher the frequency of AC the lower the reactance (like resistance). The current and applied voltage are 90 degrees out of phase the current leading the voltage by this amount.
How do coupling capacitors effect the frequency response of c e amplifier?
coupling capacitors are generally used to couple the the AC component of voltage to the DC component(biased voltage) of the transistor amplifier . As we know that the capacitor itself has some reactance which is variable with the applied frequency Rc=1/wc where w=frequency in radians = 2*pi*f and f= frequency of circuit. and, V=VC+VIN VC= voltage drop on capacitor VIN= resultant voltage available for the transistor for amplification so as, frequency increases reactance decreases drop on C decreases so, voltage available for transistor increases and now you can analyse yourself for the case if frequency decreases
What is the Relationship beteen Capacitance and frequency?
AnswerThe short answer to the question is the capacitive reactance of a capacitor in a DC circuit is infinite.In a DC circuit, disregarding transient behavior and any leakage effects, a capacitor is effectively an open circuit, and so its reactance is essentially infinite.Capacitive reactance is calculated as Xc =1/(jwC) where w is the angular frequency in radians per second, w = 2*pi*f, C is in Farads, and f is in Hertz.With DC, both f and w are zero, and, theoretically, the formula,Xc =1/(jwC) = limw-->0 [1/(jwC)] becomes infinitely large. In any practical circuit, however, there is always some leakage, so the impedance of the a capacitor will be quite large, on the order of megohms, but still finite.
