Lag and Lead Are Directional - Electronic Circuits VIII: Phase, Impedance, and Active Filters Step by Step

A phase magnitude is incomplete until its direction is checked. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

A lag is a later copy

The lag case has the same 1 second shift over 8 seconds.

\text{lag} = {1\over 8}\text{ cycle}

A lead is the opposite direction

The lead case keeps the same magnitude, 1/8 cycle, but the direction label changes.

\text{lead} = {1\over 8}\text{ cycle}