Complete, Open & Short Electric Circuits

Instructor: David Wood

David has taught Honors Physics, AP Physics, IB Physics and general science courses. He has a Masters in Education, and a Bachelors in Physics.

Learn about the difference between three types of circuit: a complete circuit, an open circuit and a short circuit. Then see how much you can remember by taking a quiz.

What Is an Electric Circuit?

An electric circuit is a flow of electrons around a complete loop that powers components within that loop. It's kind of like a bunch of race cars going around a track. A circuit must contain a power supply (the start and finish line), and components that are to be powered (various obstacles on the track). The power supply could be a battery or household plug socket, and the components could be anything electrical: a light bulb, a washing machine, a television or anything else electrical you could name.

The electricity that flows around a circuit is made up of electrons, which are negatively charged particles that are found orbiting the atoms that make up matter in the universe. The flow of electrons is called electrical current. Electrons are negatively charged and opposites attract, so they're repelled from the negative end of the battery or power supply and attracted to the positive end. That's why they flow around the circuit. The battery gives the electrons new energy and they start the journey all over again.

Complete vs. Open Circuits

For a circuit to work, it has to be complete - it has to be in a complete loop from battery to component, and back to battery again. A wire in a straight line won't do anything. This is similar to how most race tracks go in a circle, and the cars complete multiple laps.

Basic Complete Circuit
Basic Circuit

If you take a normal, complete circuit and break the connection somewhere, for example by disconnecting one end of the battery, the flow of electricity will stop. This is called an open circuit. This is like blocking off the race track at a particular point, or redirecting the race track to a dead end.

Open Circuit: There is a gap in the loop.
Open Circuit: There is a gap in the loop.

Short Circuits

A short circuit is another type of non-functioning circuit, like an open circuit. But in this case, the reason it isn't working is different. In a short circuit, there is a complete circuit present, but current is flowing in a way it wasn't intended to. This is like a race car finding a short cut to the finish line and getting disqualified from the race.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account