What is a short circuit, and what chain of effects does it produce?

Select one answer.

• An unwanted low-resistance path where none should be — it drags the shorted node toward what it connects to, overloads the source into foldback or shutdown, blows a fuse, and heats the path.
• A deliberately designed connection that every board needs to work correctly, so a short circuit is always a healthy feature and never causes a rail to sag or a fuse to blow at all.
• A gap or break in a conductor that stops all current from flowing entirely, so a short circuit always shows up as an open circuit reading infinite resistance between the two affected points on the board.
• A purely cosmetic discolouration of the solder mask that has no electrical effect whatsoever, so a short circuit can safely be ignored and never needs to be located or repaired.