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If the sinusoidal voltage is given to you in the form

[tex]v(t)=V_msin({\omega}t+\phi)[/tex]

then when you represent it on the phasor diagram, it has that angle([itex]\phi[/itex]) with respect to the positive, real axis. If all you know is the current leads/lags the voltage, then set one of the phasors as your reference, and the other phasor will either lead or lag that phasor depending on the orientation that you went with. I usually have voltage as my reference, and if the current lags (purely inductive), then the current phasor will be -90 degrees from the reference voltage phasor. If it leads in a purely capacitive network, the opposite is true.

For example, [itex]V_{RMS}e^{j0}[/itex] and [itex]I_{RMS}e^{-j90}[/itex] is the same as [itex]V_{RMS}e^{j90}[/itex] with [itex]I_{RMS}e^{j0}[/itex] because ultimately the phasor is rotating counterclockwise about the origin, at 90 degrees with respect to each other.

[tex]v(t)=V_msin({\omega}t+\phi)[/tex]

then when you represent it on the phasor diagram, it has that angle([itex]\phi[/itex]) with respect to the positive, real axis. If all you know is the current leads/lags the voltage, then set one of the phasors as your reference, and the other phasor will either lead or lag that phasor depending on the orientation that you went with. I usually have voltage as my reference, and if the current lags (purely inductive), then the current phasor will be -90 degrees from the reference voltage phasor. If it leads in a purely capacitive network, the opposite is true.

For example, [itex]V_{RMS}e^{j0}[/itex] and [itex]I_{RMS}e^{-j90}[/itex] is the same as [itex]V_{RMS}e^{j90}[/itex] with [itex]I_{RMS}e^{j0}[/itex] because ultimately the phasor is rotating counterclockwise about the origin, at 90 degrees with respect to each other.

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jim hardy

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vk6kro

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In a series circuit, if there is a resistor present, the voltage across the resistor will be in phase with the current, so this will be plotted along a horizontal line and other voltages will be plotted relative to this.

The current in all components of a series circuit is the same, but the phase of the voltage will vary depending on the component.

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