Maybe the Dell Inspiron runs on DC. So why does the nameplate say AC 100-240V?

My Compaq laptop says 110-240 v 50-60 Hz. I use a plug adapter with it in Europe. It also runs on the battery, DC. Unless your Dell says 50 Hz you run the risk of frying something inside.

Motors rated for 60 Hz will run OK on 50 Hz, but at 5/6 of the speed. They don't burn out. But 50 Hz motors running on 60 Hz can pop because they run at 6/5 of rated speed and therefore consume 6/5 of the rated amperage.

The plate on the actual laptop will say ##V DC, ##A. The power cord says 100-240V AC. Into the power cord you can plug any voltage in that range, and out of the power cord comes the DC voltage required by the laptop.

There is no universal DC voltage standard for laptops, that's why you can't use a ThinkPad powercord with a Dell computer, etc.