The reason for the total voltage drops across the capacitance and inductance IN AN AC CIRCUIT has to do with the different phase angles of the voltages.First, current is the same value and same phase angle everywhere in a series circuit. But, voltage across a capacitor lags current by 90 degrees (capacitor current leads voltage). Next, voltage across a pure inductance leads current by 90 degrees (inductor current lags voltage).The rule that all voltages in a series circuit have to add to the supply voltage still applies, but in this case, the voltage drops are added VECTORALLY, not arithmetically. If you were to graph this addition, you would show any resistance voltage in phase with the current, the capacitor voltage at -90 degrees to the current and the inductor voltage at +90 degrees to the current, for a phase difference between them of 180 degrees, cancelling each other out.In a series resonant circuit, the impedances of the capacitor and inductor cancel each other. The only impedance to the flow of current is any resistance in the circuit. Since real-life inductors always have some resistance, at least there is always some resistance in a series resonant circuit.
In a pure (ideal) capacitive circuit, current leads voltage by 90 degrees.
The circuit becomes a pure resistance circuit where current and voltage are in phase with each others.
The voltage and current sine waves cross the zero line at the same time and going in the same direction. The phase angle is 0°. They are said to be in-phase.
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.
A phase diagram in a series LCR circuit shows the phase relationship between current and voltage at different frequencies. It helps in understanding the leading or lagging nature of current with respect to voltage. The diagram typically shows a phase shift between voltage and current, with the direction and magnitude of the shift depending on the circuit's impedance at a given frequency.
The phase angle between voltage and current in a purely resistive circuit is zero. Voltage and current are in phase with each other.
The reason for the total voltage drops across the capacitance and inductance IN AN AC CIRCUIT has to do with the different phase angles of the voltages.First, current is the same value and same phase angle everywhere in a series circuit. But, voltage across a capacitor lags current by 90 degrees (capacitor current leads voltage). Next, voltage across a pure inductance leads current by 90 degrees (inductor current lags voltage).The rule that all voltages in a series circuit have to add to the supply voltage still applies, but in this case, the voltage drops are added VECTORALLY, not arithmetically. If you were to graph this addition, you would show any resistance voltage in phase with the current, the capacitor voltage at -90 degrees to the current and the inductor voltage at +90 degrees to the current, for a phase difference between them of 180 degrees, cancelling each other out.In a series resonant circuit, the impedances of the capacitor and inductor cancel each other. The only impedance to the flow of current is any resistance in the circuit. Since real-life inductors always have some resistance, at least there is always some resistance in a series resonant circuit.
a. the current and voltage in phase
In a pure inductive circuit, the relationship between current and voltage is such that the current lags behind the voltage by a phase angle of 90 degrees. This means that the current and voltage are out of phase with each other, with the current reaching its peak value after the voltage has reached its peak value.
Because current and voltage are in proportion to each other, by Ohm's law.
The phase angle between voltage and current in a purely inductive circuit, under ideal circumstances where there is no resistance at all, is 90 degrees.
In a pure resistive circuit the voltage and current are in phase. In an inductive circuit they are fro zero to 180 degrees out of phase. If they are in phase the Power Factor is 1 and 180 degrees the PF is zero. The exact amount of the phase difference depends on the specific circuit.
Voltage and current will be in phase for a purely resistive load. As a load becomes more inductive or capacitive, the phase angle between voltage and current will increase.
because of the reactances in the circuit
When an alternating voltage is applied to a purely resistive circuit, the resulting current is in phase with the voltage.
In a purely capacitive circuit, the current and the components have a relationship where the current leads the voltage by 90 degrees. This means that the current and voltage are out of phase in a purely capacitive circuit.