Table of Contents
What is lead and lag in AC circuits?
Leading and lagging current are phenomena that occur as a result of alternating current. In a circuit with alternating current, the value of voltage and current vary sinusoidally. In this type of circuit, the terms lead, lag, and in phase are used to describe current with reference to voltage.
How do you know if you have lead or lag?
They are determined by the sign of the phase angle between the current and voltage waveforms. The term ‘leading power factor’ is used where the load current leads the supply voltage, whereas the term ‘lagging power factor’ is used where the load current lags behind the supply voltage.
What is a lead lag circuit?
Definition: A lag lead compensator is a type of electrical network that generates phase lag as well as phase lead in the output signal at different frequencies when a steady-state sinusoidal input is provided to it. Generally, at low-frequency phase lag characteristics is noticed in the output of the circuit.
Does the current in an AC circuit lag lead?
The circuit is purely resistive, i.e., it is non-inductive. Therefore, current and voltage in the circuit are in the same phase. Therefore, current in the circuit leads the voltage by phase angle ϕ.
How do you calculate phase lag?
The phase difference is typically measured as the difference between the positive zero crossings, however any two analogous points on the waveform can be used. This is usually expressed in degrees (the difference in zero crossings divided by the total period of the wave multiplied by 360 degrees).
What are lag indicators?
A lagging indicator is a financial sign that becomes apparent only after a large shift has taken place. Therefore, lagging indicators confirm long-term trends, but they do not predict them. Looking at lagging indicators is one way to confirm whether a shift in the economy has actually occurred.
Does the current in an AC circuit lag lead or remain in phase with a voltage of frequency f apply to the circuit when I f/f resonance II F F resonance III F F resonance?
That is , there is net inductive reactance in the circuit . Hence current will lag behind the applied voltage. That is , there is net capacitive reactance in the circuit . Hence current will lead the applied voltage.
Which power factor is good leading or lagging?
Comparison Chart
| Basis for Comparison | Leading Power Factor | Lagging Power Factor |
|---|---|---|
| Value | Exists between -1 to 0. | Exists between 0 and 1. |
| Reactive component | Negative | Positive |
| Examples of respective loads | Capacitive load: Electrical motors, capacitor, radio circuits, etc. | Inductive load: Power generator, inductor, relays, etc. |