Chapter 34: Electric Current Practice Flashcards

Vocabulary terms and definitions covering the concepts of electric current, voltage, resistance, Ohm's law, and electric power as detailed in the Chapter 34 lecture notes.

Electric Current

The flow of electric charge; in solid conductors, it is carried by electrons while in fluids it can involve ions and electrons.

Potential Difference

The difference in potential (voltage) between the ends of a conductor, which provides the necessary pressure for charge to flow.

Conduction Electrons

Electrons in solid conductors that are free to move throughout the atomic network and carry the electric charge.

Ampere ($A$)

The unit for measuring electric current, equivalent to the flow of $1\text{ coulomb}$ of charge ($6.24\text{ billion billion electrons}$) per second.

Voltage Source

Something that provides a potential difference, such as batteries or generators, to maintain a continuous flow of electrons.

Voltage

The potential energy per coulomb of charge available to electrons moving between terminals; it provides the "electric pressure."

Electric Resistance

The resistance a conductor offers to the flow of charge, determined by the material's conductivity, thickness, length, and temperature.

Ohm ($\Omega$)

The unit used to measure electric resistance.

Ohm’s Law

The relationship stating that current is proportional to voltage and inversely proportional to resistance, expressed as $I = \frac{V}{R}$.

Resistors

Circuit elements used to regulate the current inside electric devices, often color-coded to indicate their resistance value.

Direct Current ($DC$)

A flow of charge that always moves in one direction through a circuit.

Alternating Current ($AC$)

Electric current that repeatedly reverses direction, with electrons alternating back and forth about relatively fixed positions.

Electric Power

The rate at which electrical energy is converted into another form, calculated as $\text{current} \times \text{voltage}$ ($P = I \times V$).

Watt ($W$)

The unit of power, where $1\,\text{watt} = (1\,\text{ampere}) \times (1\,\text{volt})$.

Kilowatt-hour

A unit representing the amount of energy consumed in $1\,\text{hour}$ at the rate of $1\,\text{kilowatt}$ ($1000\,\text{watts}$).