Section 25.5 Electric Current
Exercises Warm-up Activity
1.
Within a circuit, there are tiny positive charges that are free to move. What do you think is happening to all of those tiny positive charges in a simple circuit with a battery and a light bulb?
The voltages across different elements of a circuit produce electric fields within the elements that help move the charges along, producing a current.
There are two types of current that are typically discussed: conventional current and electron current. Moving forward, we will use the word "current" to refer to conventional current, the flow of positive charges from the positive end of the battery to the negative end of the battery, as is the standard way of discussing current in circuits. Electron current flows in the opposite direction of conventional current.
Definition 25.5.1. Electric Current.
Electric Current is the flow of electric charge and has units of Amps (\(\mathrm{C}/\mathrm{s}\)). It is defined as the rate of positive charge flowing past a given point in a circuit per unit time:
\begin{equation*}
I = \frac{dq}{dt}
\end{equation*}
Exercises Activities
1.
Recall the circuit (
Circuit Diagram) from
Voltage. Do you think that the current passing through element B is greater than, less than, or equal to the current passing through element A? Explain your answer.
