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'Current lags voltage' means that in the AC cycle the voltage peaks and the current peaks a little time (a fraction of a cycle) later. This happens with electrical loads like motors.
When the current lags, there is a small period in each half-cycle when the voltage has reversed and the current has not reversed yet. This causes power to flow back into the supply from the load. So there is a loss of average power fed to the load for a given voltage and current.
In this situation the power is the voltage times the current times the power factor, and the power factor is the cosine of the angle by which the current lags the voltage (counting 360 degrees as a full cycle).
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What cause the voltage t lead current in an ac circuit?
Voltage leads current or, more specifically current lags voltage, in an inductive circuit. This is because an inductor resists a change in current.
In a pure inductance circuit the current lags the voltage by what degree?
90 degrees
Why current lagging in the coil?
The coil consists of inductance. Due to inductance the current lags the voltage. So, the power factor is lagging.
Voltage current relation in passive circuit?
in passive circuit it depends on the type of load 1. if the load is purely resistive the voltage and current will be in phase 2.if the load is purely inductive the current lags the voltage by 90 dgree 3.if the load is purely capacitive the currents leads the voltage by 90 degree
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 relationship between voltage and current in an inductive circuit?
Current lags voltage in an inductive circuit. The angle by which it lags depends on the frequency of the AC, and on the relative size of the inductance compared to the resistance in the circuit.
What cause the voltage t lead current in an ac circuit?
Voltage leads current or, more specifically current lags voltage, in an inductive circuit. This is because an inductor resists a change in current.
In a pure inductance circuit the current lags the voltage by what degree?
90 degrees
Would you compare generator current to line voltage to determine if your leading or lagging?
It's always the current that determines 'leading' or 'lagging' -i.e. the angle by which the current leads or lags the voltage.
What is the phase angle between voltage and current in a purely capacitive circuit?
Current leads voltage (or voltage lags current) by 90° in a purely capacitive circuit. Try to remember it this way: capacitors resist change in voltage, hence the voltage lags (they resist voltage change because the voltage first goes to charging up the electric field in the capacitor).Inductors resist change in current (energy in an inductor is in the form of magnetic fields, which are caused by the current through the wire). Remember an inductor is a coil (like an electromagnet, or a transformer).
What is the bahaviorS of the INDUCTOR in ac supply?
Because of Ac supply, current lags voltage by 90 in Inductor.
Why current lead voltage in coil?
because a coil is an inductor,for current leads voltage in an inductorAnswerIt doesn't! Current lags voltage in a coil. In a purely-inductive circuit, the current lags the supply voltage by 90 degrees. The reason for this is 'self inductance'. Whenever a current changes, a voltage is induced into the coil which opposes that change in current. The maximum self-induced voltage occurs when the rate of change in current is greatest. The greatest positive rate of change of a.c. current occurs when that current is passing through the zero axis of its waveform, so the greatest (negative) induced voltage occurs at thatsame point, which is one-quarter of the wavelength, or 90 degrees. In accordance with Kirchhoff's Voltage Law, the supply voltage must be in antiphase with the induced voltage. So when the peak induced voltage is negative, the peak applied voltage must be positive. Or, to put it another way, the peak value of the applied voltage must occur 90 degrees before the peak value of the current -so the current lags the applied voltage by 90 degrees.
What is AC voltage terminology - in phase - mean?
If the current rises and falls with the voltage, then the two are said to be 'in phase'; this occurs in a purely-resistive circuit. For inductive or capacitive circuits, the current either lags or leads the voltage.
Why current lagging in the coil?
The coil consists of inductance. Due to inductance the current lags the voltage. So, the power factor is lagging.
Voltage current relation in passive circuit?
in passive circuit it depends on the type of load 1. if the load is purely resistive the voltage and current will be in phase 2.if the load is purely inductive the current lags the voltage by 90 dgree 3.if the load is purely capacitive the currents leads the voltage by 90 degree
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.
Why power factor lags?
When there is an inductive element in the circuit, the current lags behind the voltage. an ideal inductor will make the current lag behind the voltage by 90 degrees..a capacitive element on the other hand will make the current lead the voltage (ideally by 90deg). That's why capacitors in parallel with the system are used a lot for power factor correction
