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Does the current in a pure capacitive circuit lead or lag the applied voltage?
Wiki User
∙ 11y ago
Just remember our friend ELI the ICE man!
E is voltage, I is current, L is inductance, and C is capacitance.
ELI
In an inductively reactive circuit (L), the voltage (E) comes first, then the current (I) lags behind.
ICE
In a capacitively reactive circuit (C), the current (I) leads, then the voltage (E) comes later.
Note that while your assumption (in the stated question) is correct, an engineer or electrician would not say it that way. The voltage waveform is the constant, and the current waveform is said to lead or lag. This is because reactive or non-linear loads distort the current. If you look at a power-factor meter, and it says leading or lagging, it is referring to the current. It would be more accurate to re-phrase your question: In a capacitive reactive circuit does the current lead the voltage? Yes!
Answer #2:
Another method I learned from one of my EE professor is that in an inductor the current lags the voltage because the electrons get dizzy going through all of those loops (coils) in the inductor and "lag" behind the voltage.
Wiki User
∙ 13y ago
Wiki User
∙ 9y agoThere has to be current before there is voltage. If a battery is connected via a resistor to a capacitor, the initial current is just V/R. Charge (current times time) flows into the capacitor and its voltage rises until it reaches the battery voltage, when the capacitor is fully charge and no more current flows.
In an AC circuit the current in the capacitor leads the voltage by one quarter of a cycle, or 90 degrees of phase.
Important equations for a capacitor:
Q=CV . . . charge = capacitance (in Farads) times voltage
I = C dV/dt . . . current = capacitance times rate of change of voltage.
In an AC circuit, replace d/dt by jw where w = 2.pi times frequency:
I = jwCV
Wiki User
∙ 15y agoYes. In an inductive reactive circuit the voltage leads the current by 90 degrees. For an AC circuit, the voltage will follow a cosine wave form and the current will follow a sine wave form.
Wiki User
∙ 14y agoleading. as it carries a leading current
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How many degrees are the current and voltage out of phase in a pure capacitive circuit?
In a pure (ideal) capacitive circuit, current leads voltage by 90 degrees.
What is a capacitive reactive circuit?
A circuit that has only a capacitor in it. Or the net reactance is below zero, making it capacitive. The current leads the voltage in a negative (capacitive) reactive circuit.
Why is capacitive voltage higher than inductive voltage in an R-L-C circuit?
It isn't necessarily so. The capacitive voltage is the product of the current and capacitive reactance, while the inductive voltage is the product of the current and the inductive reactance. So it depends whether the capacitive reactance is greater or smaller than the inductive reactance!
What is it mean to say that an alternating current leads or lags an alternating emf?
It is another way of saying that the circuit is capacitive reactive circuit. Look up the mnemonic ELI the ICE man. ELI, voltage leads the current in an inductive circuit. ICE, current leads the voltage in a capacitive circuit.
What is lagging and leading current?
Leading and lagging currents are not so much "currents" as they are "situations" or "conditions" in an electrical circuit. Reactive characteristics, if there are any, will not let voltage and current be in phase in a circuit. (Unless they are equal, and this will be true at only one frequency.) In some circuits, current leads voltage (or voltage lags current), and in other circuits, current lags voltage (voltage leads current), depending on the circuit and also on the frequency of the applied signal. In a capacitor, current leads voltage, and in an inductor, current lags voltage. This carries over to circuits that exhibit primarily capacitive or inductive characteristics. Additionally, reactance varies with frequency. As a given circuit with inductance and capacitance is evaluated, at some frequencies, it will appear capacitive, and current will lead voltage. At other frequencies, the circuit will appear inductive, and current will lag voltage. Only at a frequency where the reactances are equal will the current and voltage be in phase. The ideas here are best reviewed after achieving an understanding of the nature of inductance and capacitance, the associated reactances, and the way frequency affects these characteristics.
What is the applied voltage to a resistive capacitive circuit?
this is the amount of voltage a circuit can hold.
In a capacitive AC circuit the current is?
leading the voltage.
How many degrees are the current and voltage out of phase in a pure capacitive circuit?
In a pure (ideal) capacitive circuit, current leads voltage by 90 degrees.
What happens to current flow in a capacitive circuit in comparison to voltage?
The current leads the voltage by 90degree....
What is a capacitive reactive circuit?
A circuit that has only a capacitor in it. Or the net reactance is below zero, making it capacitive. The current leads the voltage in a negative (capacitive) reactive circuit.
A circuit with a lagging current means the circuit is?
Inductive. Voltage (E) leads current (I) in an inductive (L) circuit and current (I) leads voltage (E) in a capacitive (C) circuit. (ELI the ICEman)
What is a reactive circuit?
A circuit that has only a capacitor in it. Or the net reactance is below zero, making it capacitive. The current leads the voltage in a negative (capacitive) reactive circuit.
Why is capacitive voltage higher than inductive voltage in an R-L-C circuit?
It isn't necessarily so. The capacitive voltage is the product of the current and capacitive reactance, while the inductive voltage is the product of the current and the inductive reactance. So it depends whether the capacitive reactance is greater or smaller than the inductive reactance!
What is it mean to say that an alternating current leads or lags an alternating emf?
It is another way of saying that the circuit is capacitive reactive circuit. Look up the mnemonic ELI the ICE man. ELI, voltage leads the current in an inductive circuit. ICE, current leads the voltage in a capacitive circuit.
When the frequency of an applied voltage is increased the capacitive reactance of a circuit will?
Since capacitive reactance is inversely-proportional to the supply frequency, as the frequency is increased, the reactance will decrease.
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
When an alternating voltage is applied to purely resistive circuit what happens?
When an alternating voltage is applied to a purely resistive circuit, the resulting current is in phase with the voltage.
