AP Physics 2: Algebra-Based Practice Quiz: Electric Current
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Test your understanding with short quizzes. This quiz has 10 questions to check your progress.
Question 1 of 10
All Questions (10)
A) The total amount of charge stored in a wire.
B) The speed of an individual electron in a circuit.
C) The rate of flow of electric charge through a cross-sectional area.
D) The electric potential difference that causes charge to move.
Correct Answer: C
The provided content defines current as 'the rate at which charge passes through a cross-sectional area of a wire.' This directly corresponds to the rate of flow of electric charge.
A) A uniform magnetic field.
B) An electric potential difference.
C) The thermal energy of the wire.
D) The gravitational force on the charges.
Correct Answer: B
The content states that 'Electric charge moves in a circuit in response to an electric potential difference, sometimes referred to as electromotive force, or emf.'
A) In the direction of the flow of negative charges.
B) In the direction that positive charges would move.
C) In the direction of the strongest component of the electric field.
D) It is a vector quantity aligned with the z-axis in a coordinate system.
Correct Answer: B
The text specifies that 'The direction of current is associated with what the motion of positive charge would be.' This is the established convention, regardless of the actual charge carriers (e.g., electrons).
A) 0.33 A
B) 3.0 A
C) 20 A
D) 75 A
Correct Answer: B
Using the formula $I=\frac{\Delta q}{\Delta t}$, where $\Delta q = 15$ C and $\Delta t = 5$ s. The current is $I = \frac{15 \text{ C}}{5 \text{ s}} = 3.0$ A.
A) From left to right.
B) From right to left.
C) Perpendicular to the wire.
D) There is no conventional current because the charges are negative.
Correct Answer: B
The direction of conventional current is defined as the direction of positive charge flow. A flow of negative charges (electrons) from left to right is electrically equivalent to a flow of positive charges from right to left.
A) Joule / Coulomb
B) Volt / second
C) Coulomb / second
D) Second / Coulomb
Correct Answer: C
The equation $I=\frac{\Delta q}{\Delta t}$ defines current as charge ($\Delta q$, in Coulombs) per unit time ($\Delta t$, in seconds). Therefore, one Ampere is equivalent to one Coulomb per second.
A) It is a vector quantity because it has both a magnitude and a direction.
B) It is a scalar quantity that is assigned a direction by convention but does not follow the rules of vector addition.
C) It is a vector quantity that always points opposite to the direction of the electric field.
D) It is a fundamental constant of nature.
Correct Answer: B
The provided content explicitly states, 'Although current is not a vector quantity, it does have a direction.' This indicates it is a scalar with a directional convention.
A) 0.125 C
B) 8.0 C
C) 22.5 C
D) 50 C
Correct Answer: D
By rearranging the formula $I=\frac{\Delta q}{\Delta t}$ to solve for charge, we get $\Delta q = I \cdot \Delta t$. Plugging in the values, $\Delta q = (2.5 \text{ A}) \cdot (20 \text{ s}) = 50$ C.
A) It is halved.
B) It remains the same.
C) It is doubled.
D) It is quadrupled.
Correct Answer: C
From the equation $\Delta q = I \cdot \Delta t$, charge is directly proportional to the time interval. If the current $I$ is constant and the time $\Delta t$ is doubled, the total charge $\Delta q$ must also double.
A) A mechanical force pushing charges.
B) The mass of the charge carriers.
C) An electric potential difference.
D) The resistance of the medium.
Correct Answer: C
The content states that 'Electric charge moves in a circuit in response to an electric potential difference, sometimes referred to as electromotive force, or emf ($\mathcal{E}$).' This shows that emf is another term for the electric potential difference that drives current.