alternating and direct currents

Question 1

what is an alternating current (a.c)?

Answer 1

one that continuously changes its direction going back and forth around a circuit.

Question 2

what is a direct current (d.c)?

Answer 2

one that is steady, constantly going the same way around a circuit, from positive to negative.

Question 3

do electric cells (batteries) produce a.c or d.c?

Answer 3

direct current (d.c)

Question 4

is mains electricity a a.c or a d.c

Answer 4

an alternating current (a.c)