Answer: D) chemical cells or batteries
Explanation: Direct Current is an electric current in which electrons flow steadily in a single direction. Alternating Current is an electric current that periodically reverses its direction.
As alternating current can be converted to voltage levels with a single component using a transformer, and thus are used to transmit electricity over long distances.
A) Generators use electromagnetic induction to convert mechanical energy into electrical energy and produce alternating current.
B) Wall sockets are a source of alternating current.
C) Electromagnetic or magnetic induction is the production of an electromotive force across an electrical conductor in a changing magnetic field and produce alternating current.
D) Batteries convert chemical energy into electrical energy by a chemical reaction and produce direct current.
