Extra exam question E4A10

WhyLine triggering is the most effective trigger mode for using an oscilloscope to measure a linear power supply's output ripple. Line triggering, which syncs the oscilloscope's sweep to the AC power line frequency, is the most effective trigger mode for viewing a linear power supply's output ripple, since that ripple is directly tied to the rectified AC line frequency it's derived from, answer D. Single-shot, edge, and level triggering can display a ripple waveform too, but they don't lock onto the specific AC-line-related timing that makes the ripple pattern easiest to read and stable on screen.