Current

High School

Definition

The rate of flow of electric charge through a conductor, measured in amperes. Conventional current is treated as the flow of positive charge, and it is driven by a voltage across the circuit.

Worked examples

\(I = \frac{Q}{t} = \frac{12\,\)C\(}{3\,\)s\(} = 4\,\)A\(\)

Current is charge per time: 12 coulombs flowing in 3 seconds gives 4 amperes.

A circuit with a 9 V battery and 3 Ω resistor has a current of 3 A flowing through it.

Voltage drives the current; more voltage or less resistance means more current flows.

Common mistakes

Current is used up as it flows through a circuit → Current is the same at all points in a series circuit Charge is conserved—current measures flow rate, which stays constant in series.
Electrons flow from positive to negative terminal → Electrons flow from negative to positive; conventional current is opposite Conventional current direction is positive to negative, but electrons move the other way.
\(I = V \times R\) → \(I = \frac{V}{R}\) Ohm's law: current equals voltage divided by resistance, not multiplied.

Where you'll use it next

You'll use current when analyzing series and parallel circuits, calculating power with \(P = IV\), studying Ohm's law, and exploring magnetism and electromagnetism in later physics courses.

Found in 1 StudyPug lesson

Mastering Electric Current: From Basics to Advanced Circuits

Physics 11

Dive into the world of electric current! Learn about circuit types, Ohm's Law, and safety measures. Boost your understanding of this fundamental physics concept and its real-world applications.

11th Grade11th