What does it mean if something has reversed polarity?

Answer by  Binome (1975)

Electronics all have a negative and a positive end. Reversed polarity simply means that the negative and positive ends have been switched.

Answer by  Amber40 (24961)

It means the power supply of the device has the current moving in the wrong direction. As if you put a + terminal to the - of a battery.

Answer by  petersmith (15)

Most electrical devices will only work when their positive and negative terminals of their battery or power supply are connected the right way round. Something has reversed polarity when the device and power supply markings are not aligned (negative '-' connected to positive '+').