Generator cord gauge
Cord gauge (AWG) sets how much current a generator cord can carry safely and how much voltage it loses over distance: 10 AWG for 30 A circuits, 6 AWG for 50 A, and thicker (lower-number) wire the longer the run.
Undersized cords overheat and starve appliances of voltage — a motor that receives low voltage draws more current and runs hotter, which is how refrigerator compressors die during outages. For ordinary extension cords to individual appliances, 12 AWG is a sensible minimum for anything with a motor.
Since generators must sit at least 20 feet from the house, voltage drop is not theoretical: at 20–50 feet, buy the gauge rated for the full circuit amperage — a 30 A L14-30 cord should be 10 AWG, a 50 A cord 6 AWG.