Meaning : A radioactive element of the actinide series. Found in uranium ores.
Synonyms : actinium, atomic number 89
Meaning : An electric current that reverses direction sinusoidally.
Example :
In the US most household current is AC at 60 cycles per second.
Synonyms : alternating current, alternating electric current
An electric current that flows in one direction steadily.
dc, direct current, direct electric current