The Hole On the Top Of a Lollipop Stick
Lollipops will always be a kid’s favorite. No kids’ party would be complete without them, and converting the plastic stick with a hole into a makeshift whistle was one of the finest parts of eating a lollipop. That hole serves a function, as entertaining as it was.
During the process of pouring hot, melted candy into the mold, some of the candy falls into the hole and hardens, ensuring that the candy remains on the stick without coming off.
The Threaded Bands On Audio Jacks
If you were to examine an audio jack attentively, you would see that it has deep ridges. These bands are there to make it more difficult to insert and remove the jacks when they are connected in, although this is only one of their roles.
When sound is transmitted, the threaded bands are comprised of an insulating substance that protects the wires. In addition, the number of ridges on a jack indicates which end goes where.