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What happens when an electric potential difference (voltage) is applied across a conductor?
It causes charge carriers (usually electrons) to move, resulting in an electric current.
What happens when the radius of a wire increases, assuming drift velocity and other factors remain constant?
The current through the wire increases because there is a larger cross-sectional area for charge flow ($I = nqv_dA$).
What happens when the charge carrier density in a conductor increases?
The electric current increases, assuming drift velocity and other factors remain constant ($I = nqv_dA$).
What is the effect of increasing the resistivity of a material on the electric field required to maintain a certain current density?
A higher electric field is required, as described by the equation $\vec{E} = \rho \vec{J}$.
What is electric current?
The flow of electric charge through a conductor, driven by an electric potential difference (voltage).
What is drift velocity?
The average velocity of charge carriers (e.g., electrons) in a conductor due to an electric field.
What is electromotive force (emf)?
The electric potential difference $(\mathcal{E})$ that drives charges to move, creating an electric current.
What is charge carrier density?
The number of charge carriers (e.g., electrons) per unit volume in a conductor, denoted by 'n'.
What is current density?
A measure of how much electric current is flowing per unit area; a vector quantity with both magnitude and direction.
What is conventional current?
The direction of electric current defined by the movement of positive charges, which is opposite to the flow of electrons.
What is resistivity?
A property of a material that quantifies how strongly it resists the flow of electric current. Represented by $\rho$.
What are the differences between conventional current and electron flow?
Conventional Current: Direction positive charges would move. | Electron Flow: Actual movement of electrons, opposite to conventional current.
What are the differences between resistivity and resistance?
Resistivity: A property of the material. | Resistance: Depends on the material's geometry (length and area).
What are the differences between current and current density?
Current: Scalar quantity representing the rate of charge flow. | Current Density: Vector quantity representing current per unit area with direction.