AC

Meanings

1. 1abbreviation

   A system that cools and controls the humidity of indoor air.

   Grammar: Used like a noun: turn on the AC; the AC is broken.

   Patterns

   • turn on the AC
   • turn off the AC
   • the AC is on

   It's so hot in here—could you turn on the AC?

   The AC in my office is too cold, so I brought a sweater.

   We had to call a technician because the AC stopped working.

2. 2abbreviationtechnical

   Electric current that regularly reverses direction, used in most homes.

   Grammar: Technical; often contrasted with DC (direct current).

   Patterns

   • AC power
   • AC adapter
   • AC current

   This device runs on AC power, so you need to plug it in.

   The adapter converts AC to DC for the laptop.

   In AC circuits, the current changes direction many times per second.

Common combinations

AC unit

They installed a new AC unit in the living room.

AC adapter

Don't forget your AC adapter for the trip.

AC power

The lab uses AC power for all its equipment.

turn on the AC

Please turn on the AC; it's boiling in here.

Synonyms and how they differ

air conditioning

The full term; AC is just the abbreviation, common in everyday speech.

Commonly confused: AC or DC?

Practice

Make it your own

Write a sentence using “AC”, then check it and compare it with the examples above.

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