Online College Courses for Credit

Electric Circuits

Electric Circuits

Author: Nathan Lampson

We use electric currents everyday to power electric devices, such as phones, computers, and calculators. Explore what an electrical current is, and how we measure current, voltage, and resistance in amps, volts, and ohms. You will also learn Ohm's Law which is used to calculate current, voltage, and resistance of simple electrical circuits.

See More
Fast, Free College Credit

Developing Effective Teams

Let's Ride
*No strings attached. This college course is 100% free and is worth 1 semester credit.

37 Sophia partners guarantee credit transfer.

299 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 32 of Sophia’s online courses. Many different colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.



Electrical circuits are pathways where free electrons can move.  The movement of free electrons is called a current.  The force that moves electrons through a circuit is called a voltage.  Opposition to the movement of free electrons is called resistance.


The formula E=IR can be used to calculate the relationship between voltage, current, and resistance in a circuit. There are three different versions of the formula that can be used to calculate voltage, current, or resistance.


E=Voltage (measured in Volts (V))

I=Current (measured in Amps (A))

R=Resistance (measured in Ohms (Ω))







If a circuit has a resistance of 3Ω and a voltage of 12V what is the current of the circuit?





I=E/R is used to solve for current.





The current of the circuit is 4A.

Electric Circuits