AP Physics 2 Unit 12 Review: Magnetism and Electromagnetism

Q: What's on the AP Physics 2 Unit 12 progress check (MCQ and FRQ)?

The AP Physics 2 Unit 12 progress check includes both MCQ and FRQ parts drawn from all four unit topics: magnetic fields and force on a moving charge, magnetism and moving charges, magnetism and current-carrying wires, and electromagnetic induction. The MCQ part tests conceptual reasoning and quantitative skills, while the FRQ part typically asks you to analyze scenarios involving magnetic forces or induced EMF. For matched practice that mirrors the progress check format, visit /ap-physics-2-revised/unit-12 .

Q: How do I practice AP Physics 2 Unit 12 FRQs?

The best way to practice AP Physics 2 Unit 12 FRQs is to focus on the two highest-yield topics: electromagnetic induction (Topic 12.4) and magnetic fields and force on a moving charge (Topic 12.1). Free-response questions in this unit typically ask you to derive or apply the force on a charged particle, explain how changing magnetic flux induces an EMF, or analyze a circuit with an induced current. Practice by writing out full solutions, showing your reasoning with diagrams, and checking that your units and sign conventions are correct. Find Unit 12 FRQ practice at /ap-physics-2-revised/unit-12 .

Q: Where can I find AP Physics 2 Unit 12 practice questions?

For AP Physics 2 Unit 12 practice questions, including multiple-choice and practice test sets covering magnetic fields, moving charges, current-carrying wires, and electromagnetic induction, head to /ap-physics-2-revised/unit-12 . That page collects MCQ drills and full practice tests aligned to the 12-15% exam weight of this unit, so you can target exactly the concepts that show up most on the AP exam.

Q: How should I study AP Physics 2 Unit 12?

Start by building a solid picture of how magnetic fields are created and how they exert forces on moving charges, since Topics 12.1 and 12.2 form the foundation everything else rests on. Then work through Topic 12.3 on current-carrying wires, paying close attention to the right-hand rule and how wire geometry affects field direction. Save dedicated time for Topic 12.4 on electromagnetic induction, which is the most FRQ-heavy topic in the unit. Draw diagrams for every problem, practice converting between field, force, and flux relationships, and do timed MCQ sets to build the quick conceptual recall the exam rewards. All four topics are organized at /ap-physics-2-revised/unit-12 .

12–15% of AP multiple choice
4 topics
AP exam review verified for 2027

Magnetism and electromagnetism is the study of how moving electric charges produce magnetic fields and how changing magnetic fields produce electric potential differences. The unit links the Lorentz force law, Biot-Savart-style reasoning for current-carrying wires, and Faraday's law into a unified picture of how electricity and magnetism interact.

Fiveable's AP Physics 2 Unit 12 review covers 4 topics, with guided practice questions for the unit.

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AP Physics 2 unit 12 topics

12.1

Magnetic Fields

Magnetic fields are vector fields produced by magnetic dipoles. Field lines form closed loops and never originate from monopoles. Material responses range from ferromagnetic (strong, permanent) to paramagnetic (weak, temporary) to diamagnetic (weak opposition). Magnetic permeability mu quantifies how a material responds to an external field.

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12.2

Magnetism and Moving Charges

A moving charge produces a magnetic field and experiences a force F_B = qvB sin theta in an external field. The force is perpendicular to velocity, so it causes circular motion (r = mv/qB) without doing work. The right-hand rule gives force direction. Velocity selectors and the Hall effect are key applications.

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12.3

Magnetism and Current-Carrying Wires

Current-carrying wires produce magnetic fields described by B = mu_0/(2pi) (I/r) for a long straight wire. The right-hand grip rule gives field direction. An external field exerts force F_B = IlB sin theta on a current-carrying wire. Parallel wires with currents in the same direction attract; opposite currents repel.

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12.4

Electromagnetic Induction and Faraday's Law

Changing magnetic flux Phi_B = BA cos theta induces an emf given by Faraday's law: |epsilon| = |Delta Phi_B / Delta t|. Lenz's law determines the direction of the induced current, which always opposes the flux change. Motional emf epsilon = Blv applies to a rod moving through a uniform field.

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Practice AP Physics 2 unit 12 questions

Try AP-style questions on unit 12, then use the review notes below for anything you miss.

Example stimulus-based MCQs

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diagram

Stimulus-based practice question

A particle of mass $m$ and charge $q$ moves with speed $v$ in the $xy$ -plane at angle $\theta$ above the $x$ -axis. A uniform magnetic field $B$ is directed in the positive $z$ -direction (out of the page). The particle undergoes circular motion due to the magnetic force.

answer in practice

Question

Which of the following expressions correctly represents the radius $r$ of the circular path of the particle in terms of the given quantities?

$r = \frac{mv\sin\theta}{qB}$

$r = \frac{mv\cos\theta}{qB}$

$r = \frac{mv}{qB}$

$r = \frac{qB}{mv}$

diagram

Stimulus-based practice question

A rectangular conducting loop is partially inside a region of uniform magnetic field directed into the page, as shown. The loop is pulled to the right at constant velocity v, moving out of the field region. A student claims that the induced current in the loop flows counterclockwise as viewed from the front.

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Question

Which of the following correctly evaluates the student's claim and provides valid scientific justification?

The claim is correct, because as the loop exits the field, the flux into the page decreases, so by Lenz's law the induced current must create a field into the page inside the loop, requiring counterclockwise current as viewed from the front.

The claim is incorrect, because as the loop exits the field, the flux into the page decreases, so by Lenz's law the induced current must oppose this decrease by creating a field into the page inside the loop, which requires clockwise current as viewed from the front.

The claim is correct, because the conducting rod on the right side of the loop moves through the field, and by the right-hand rule for a positive charge moving right in a field directed into the page, the force on positive charges is upward, driving counterclockwise current.

The claim is incorrect, because the magnetic flux through the loop does not change as long as the loop moves at constant velocity, so no emf is induced and no current flows.

Example FRQs

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FRQ

Magnetic force on charged particle in solenoid

4. A long solenoid of length $L = 0.60\ \text{m}$ has $N = 1200$ tightly wound turns and carries a steady current $I = 2.0\ \text{A}$ . The solenoid's axis is horizontal. A cylindrical core of radius $R = 1.5\ \text{cm}$ is placed coaxially inside the solenoid. The core material is linear and has relative permeability $\mu_r$ . A point $P$ is located on the solenoid's axis at a position well inside the solenoid (so end effects are negligible) and is at the center of the core. A proton enters the solenoid at point $P$ with speed $v = 3.0× 10^6\ \text{m/s}$ directed vertically upward, perpendicular to the solenoid's axis, as shown in Figure 1.

Figure 1. Long solenoid (L = 0.60 m, N = 1200 turns, I = 2.0 A) with coaxial cylindrical core (radius R = 1.5 cm). A proton at point P on the axis moves upward with speed v = 3.0×10^6 m/s while the magnetic field inside the solenoid points along the solenoid axis.

A student claims that the magnitude of the magnetic force on the proton at point $P$ is greater when the core material has $\mu_r = 200$ than when the solenoid contains only air (approximately $\mu_r = 1$ ).

Indicate whether the student's claim is correct or incorrect. Without manipulating equations, justify your answer by referencing how the configuration of magnetic dipoles in a material affects the magnetic field inside the solenoid and therefore the force on a moving charged particle.

Derive an expression for the magnitude of the magnetic force on the proton at point $P$ . Express your answer in terms of $N$ , $L$ , $I$ , $\mu_r$ , $v$ , and physical constants, as appropriate. Begin your derivation by writing a fundamental physics principle or an equation from the reference information.

Indicate whether the expression you derived in part B is or is not consistent with your answer from part A. Briefly justify your answer by describing how the force depends on $\mu_r$ .

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FRQ

Magnetic forces on moving charge near wire

2. A long straight wire carries a steady current I = 8.0 A upward (toward the top of the page), and a square loop of wire with N = 50 turns is placed to the right of the wire in the plane of the page, as shown in Figure 1.

Figure 1. Wire and square loop configuration

Figure dot. Force diagram for moving positive charge

Point P is 0.060 m to the right of the long straight wire. A positive charge q = +2.0 μC is moving upward at point P with speed v = 3.0 × 10^6 m/s. On the dot shown in Figure dot, representing the charge, draw and label the forces that are exerted on the charge at that instant. Each force must be represented by a distinct arrow starting on, and pointing away from, the dot.

Derive an expression for the magnitude of the net magnetic flux ΦB through the N-turn square loop due to the magnetic field of the long straight wire, in terms of μ0, I, N, L, and a. Begin your derivation by writing a fundamental physics principle or an equation from the reference information. Assume the magnetic field of a long straight wire is B(r) = μ0I/(2πr) and that the field is perpendicular to the loop's area over the entire loop.

Figure 2. Axes for magnetic field vs. distance

On the axes provided in Figure 2, sketch the expected relationship between the magnetic field magnitude B and the distance r from the long straight wire for 0.02 m ≤ r ≤ 0.20 m when the current is I = 8.0 A. Draw an arrow on your sketch to represent the direction of increasing r.

Indicate whether the magnitude of the induced potential difference across the loop during the interval is greater than, less than, or equal to the magnitude of the induced potential difference that would occur for the same current change if the loop were instead filled with air (μ = μ0). The loop is now completely filled with a linear magnetic material of relative permeability μr = 200 (so the permeability in the material is μ = μrμ0). The current in the long straight wire is then decreased at a constant rate from 8.0 A to 2.0 A in a time interval Δt = 0.50 s.

greater than
less than
equal to

Briefly justify your answer by referencing at least one feature of your answers to parts B or C and the meaning of magnetic permeability.

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FRQ

Magnetic force on moving charge near current-carrying wire

1. A very long straight wire lies in the plane of the page along the +x-direction (to the right) and carries a steady current $I = 12\ \text{A}$ . A point $P$ is located a distance $r_P = 4.0\ \text{cm}$ directly above the wire (along the +y-direction). A positive charge $q = 3.0\ \mu\text{C}$ at point $P$ moves with speed $v = 2.5× 10^5\ \text{m/s}$ in the +x-direction, as shown in Figure 1. The diameters of all conductors are small compared to all given distances.

Figure 1. A long straight wire carries current to the right (+x). A positive charge at point P, located 4.0 cm above the wire, moves to the right with speed 2.5×10^5 m/s.

Figure 2. Indicate the direction of the magnetic field at point P due to the current in the long straight wire.

Figure 3. Indicate the direction of the magnetic force on the moving positive charge at point P.

Complete the following tasks in Figures 2 and 3. Use either arrows or the symbols shown in the box above the figures for your response.

•

Indicate the direction of the magnetic field at point $P$ due to the current in the wire in Figure 2.

•

Indicate the direction of the magnetic force exerted on the moving positive charge at point $P$ in Figure 3.

ii.

At point $P$ , the wire is replaced by a long cylindrical rod made of a linear magnetic material with relative permeability $\mu_r$ . The rod carries the same current $I$ in the +x-direction and has radius $a = 1.0\ \text{cm}$ . Point $P$ remains at the same location, with $r_P = 4.0\ \text{cm}$ from the rod's axis.

Derive an expression for the magnitude of the magnetic field $B_P$ at point $P$ in terms of $I$ , $r_P$ , $\mu_0$ , and $\mu_r$ . Begin your derivation by writing a fundamental physics principle or an equation from the reference information.

Figure 4. A circular conducting loop in the plane of the page moves upward (+y) away from a long straight current-carrying wire.

Indicate whether there is a clockwise induced current in the loop, a counterclockwise induced current in the loop, or no induced current in the loop. A single circular conducting loop of radius $R = 1.0\ \text{cm}$ is placed in the plane of the page with its center a distance $r_c = 4.0\ \text{cm}$ above the long straight wire, as shown in Figure 4. The loop is then translated upward (in the +y-direction) at a constant speed $v_{\text{loop}} = 0.50\ \text{m/s}$ while the current in the wire remains constant. Assume the magnetic field produced by the wire is approximately uniform over the area of the loop and is equal to the wire's magnetic field evaluated at the loop's center (i.e., at distance $r = r_c$ from the wire).

Clockwise
Counterclockwise
There is no induced current in the loop.

Justify your answer.

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AP Physics 2 unit 12 practice test

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Unit 12 review notes

12.1

Magnetic Fields and Material Behavior

A magnetic field B is a vector field produced only by magnetic dipoles, never by isolated monopoles. Field lines always form closed loops: outside a bar magnet they run from north to south, and inside they continue from south back to north. The strength of the field from a dipole decreases with distance. A compass or any magnetic dipole placed in an external field experiences a torque that tends to align it with that field. A material's magnetic behavior depends on how its atomic dipoles respond to an external field.

Ferromagnetic materials: Iron, nickel, and cobalt have magnetic domains that align strongly with an external field and can remain aligned after the field is removed, producing permanent magnets.
Paramagnetic materials: Aluminum and titanium align weakly with an external field but lose their magnetization when the field is removed.
Diamagnetic materials: All materials show a weak opposition to an external field due to electron orbital responses; this effect is usually dominated by para- or ferromagnetism when those are present.
Magnetic permeability (mu): Measures how strongly a material magnetizes in response to an external field. Free space has the constant mu_0 = 4pi x 10^-7 T·m/A; matter has values that vary with temperature, orientation, and field strength.
No magnetic monopoles: Breaking a bar magnet always produces two smaller dipoles, each with a north and south pole. An isolated magnetic pole has never been observed.

If a bar magnet is cut in half, what are the two resulting pieces? Explain why in terms of magnetic dipoles.

Material type	Alignment with external field	Permanent magnetism possible?	Example
Ferromagnetic	Strong, domain-level alignment	Yes	Iron, nickel, cobalt
Paramagnetic	Weak alignment	No	Aluminum, titanium
Diamagnetic	Weak opposition	No	Bismuth, water

12.2

Magnetic Force on Moving Charges

A single moving charge produces a magnetic field whose direction is perpendicular to both the charge's velocity and the position vector from the charge to the field point, found using the right-hand rule. An external magnetic field exerts a force on a moving charge given by F_B = qvB sin theta. Because this force is always perpendicular to velocity, it does no work and cannot change the particle's speed, only its direction. When velocity is perpendicular to B, the particle follows a circular path with radius r = mv/(qB).

F_B = qvB sin theta: Magnitude of the magnetic force on a charge q moving at speed v through field B at angle theta between v and B. Force is zero when v is parallel to B (theta = 0 or 180 degrees) and maximum when perpendicular (theta = 90 degrees).
Right-hand rule for force: Point fingers in the direction of v, curl toward B; thumb points in the direction of force on a positive charge. Reverse for negative charges.
Circular motion in a magnetic field: When v is perpendicular to B, the magnetic force provides centripetal acceleration. Setting qvB = mv^2/r gives radius r = mv/(qB).
Velocity selector: Crossed electric and magnetic fields where F_E = qE and F_B = qvB balance, so only particles with v = E/B pass through undeflected.
Hall effect: A magnetic field perpendicular to current flow pushes charge carriers sideways, creating a measurable transverse voltage that identifies the sign and density of charge carriers.

A proton moves east in a magnetic field directed north. Use the right-hand rule to determine the direction of the magnetic force on the proton.

Condition	Angle theta	Magnetic force magnitude
v parallel to B	0 or 180 degrees	Zero
v perpendicular to B	90 degrees	Maximum: F = qvB
v at arbitrary angle	0 < theta < 90	F = qvB sin theta

12.3

Magnetic Fields and Forces from Current-Carrying Wires

A current-carrying wire produces a magnetic field that wraps around it in concentric circles. For a long straight wire, the field magnitude at perpendicular distance r is B = mu_0/(2pi) (I/r), and the direction is given by the right-hand grip rule: wrap fingers around the wire with the thumb pointing in the direction of current; fingers show the field direction. At the center of a circular current loop, the field points along the axis of the loop. When multiple wires are present, fields add as vectors. An external magnetic field exerts a force on a current-carrying wire of magnitude F_B = IlB sin theta, with direction from the right-hand rule.

B = mu_0/(2pi) (I/r): Magnetic field magnitude at distance r from a long straight wire carrying current I. Field is stronger closer to the wire and weaker farther away.
Right-hand grip rule: Thumb points in the direction of conventional current; curled fingers show the direction of the circular magnetic field lines around the wire.
F_B = IlB sin theta: Force on a wire of length l carrying current I in field B at angle theta between current direction and field. Maximum when current is perpendicular to B.
Parallel wires: Two parallel wires carrying currents in the same direction attract each other; opposite currents repel. Each wire's field exerts a force on the other's current.
Vector superposition of fields: The total magnetic field at a point from multiple current sources is the vector sum of each individual field contribution.

Two long parallel wires carry currents in opposite directions. Describe the direction of the magnetic force each wire exerts on the other and explain why.

Source	Field equation	Field direction method
Long straight wire	B = mu_0 I / (2pi r)	Right-hand grip rule
Center of circular loop	B = mu_0 I / (2R)	Right-hand rule along axis
Force on wire in external B	F = IlB sin theta	Right-hand rule (current x B)

12.4

Electromagnetic Induction and Faraday's Law

Magnetic flux Phi_B = BA cos theta measures how much of the magnetic field passes perpendicularly through a surface area A. Faraday's law states that a changing flux induces an emf: |epsilon| = |Delta Phi_B / Delta t|. Flux can change by changing B, A, or the angle theta between B and the area vector. Lenz's law gives the direction of the induced current: it always opposes the change in flux that caused it, which is a consequence of energy conservation. For a conducting rod of length l moving at speed v perpendicular to a uniform field B, the motional emf is epsilon = Blv.

Phi_B = BA cos theta: Magnetic flux through a flat surface of area A in a uniform field B, where theta is the angle between B and the area vector (perpendicular to the surface). Units are webers (Wb).
Faraday's law: |epsilon| = |Delta Phi_B / Delta t|. The magnitude of the induced emf equals the rate of change of magnetic flux through the loop. For an N-turn coil, multiply by N.
Lenz's law: The induced current flows in the direction that creates a magnetic field opposing the change in flux. If flux through a loop increases upward, the induced current creates flux downward inside the loop.
Motional emf: epsilon = Blv for a conducting rod of length l moving at speed v perpendicular to field B. The rod acts like a battery driving current through any connected circuit.
Induced current: I = epsilon / R, where epsilon is the induced emf from Faraday's law and R is the resistance of the circuit. Current flows only while flux is changing.

A square loop is pulled out of a region of uniform magnetic field directed into the page. Using Lenz's law, determine the direction of the induced current in the loop as it exits the field.

What changes	Effect on flux	Induced emf present?
B increases	Flux increases	Yes
Area of loop decreases	Flux decreases	Yes
Loop rotates (theta changes)	Flux changes	Yes
B constant, A constant, theta constant	No change	No

Key terms

Term	Definition
permeability of free space	The constant mu_0 = 4pi x 10^-7 T·m/A that relates the magnetic field produced by a current to the current itself in vacuum. Appears in the wire field equation and other magnetic field expressions.
ferromagnetic materials	Materials such as iron, nickel, and cobalt whose magnetic domains align strongly with an external field and can remain aligned after the field is removed, enabling permanent magnets.
diamagnetism	A weak magnetic response present in all materials where electron orbital motion creates dipole moments that oppose an external field. Usually masked by stronger para- or ferromagnetic effects.
circular motion	The path of a charged particle moving perpendicular to a uniform magnetic field. The magnetic force provides centripetal acceleration, giving radius r = mv/(qB).
radius of curvature	The radius r = mv/(qB) of the circular path of a charged particle in a magnetic field. Larger mass or speed increases r; larger charge or field strength decreases r.
Velocity selector	A device with crossed electric and magnetic fields where only particles with speed v = E/B pass through undeflected because the electric and magnetic forces exactly cancel.
Hall effect	A transverse potential difference that develops across a current-carrying conductor in a perpendicular magnetic field, caused by the sideways deflection of charge carriers.
induced emf	An electromotive force generated in a conductor or loop by a changing magnetic flux, calculated from Faraday's law as \|epsilon\| = \|Delta Phi_B / Delta t\|.
Induced current	The current that flows in a closed loop when an emf is induced by changing magnetic flux. Its magnitude is I = epsilon / R and its direction is given by Lenz's law.
Charged particle trajectory	The curved path of a charged particle in a magnetic field. When v is perpendicular to B the path is circular; at other angles it becomes helical.

How to review unit 12

Topics students miss most

Miss rates come from Fiveable multiple-choice practice.

12.1

Magnetic Fields

49%198 tries

12.4

Electromagnetic Induction and Faraday's Law

40%197 tries

12.3

Magnetism and Current-Carrying Wires

34%427 tries

Common unit 12 mistakes

Confusing magnetic force direction for negative charges

The right-hand rule gives the force direction for a positive charge. For a negative charge, the force is exactly opposite. Students often forget to reverse the direction when the moving particle is an electron or other negative charge.

Thinking magnetic force does work

Because the magnetic force is always perpendicular to velocity, it cannot change a particle's kinetic energy or speed. It only changes direction. Claiming that a magnetic force accelerates or decelerates a particle's speed is incorrect.

Misidentifying what angle to use in flux and force equations

In Phi_B = BA cos theta, theta is the angle between B and the area vector (perpendicular to the surface), not the angle between B and the surface itself. In F_B = IlB sin theta, theta is between the current direction and B. These are different angles and mixing them up leads to wrong signs and magnitudes.

Applying Lenz's law in the wrong direction

Lenz's law says the induced current opposes the change in flux, not the flux itself. If flux is increasing into the page, the induced current creates flux out of the page inside the loop. Students often reverse this and oppose the existing flux rather than the change.

Forgetting that the magnetic field from a wire decreases as 1/r, not 1/r^2

The field from a long straight wire follows B proportional to 1/r, not the inverse-square law that applies to point charges and gravitational sources. Doubling the distance from a wire halves the field, not quarters it.

How this unit shows up on the AP exam

Predicting force direction and magnitude from field diagrams

AP Physics 2 questions frequently present a diagram of a magnetic field region and ask you to determine the direction and magnitude of the force on a moving charge or current-carrying wire. You need to apply the right-hand rule correctly, identify the relevant angle theta, and substitute into F_B = qvB sin theta or F_B = IlB sin theta. Questions may also ask how the force changes if speed, current, or field strength is doubled.

Reasoning about electromagnetic induction scenarios

Free-response questions often describe a loop or coil in a changing magnetic field and ask you to calculate induced emf using Faraday's law, determine current direction using Lenz's law, and connect the result to circuit behavior using I = epsilon / R. Scenarios include a rod sliding on rails, a loop being pulled out of a field region, and a coil with changing area or field strength. You may also need to explain qualitatively why the induced current direction follows from energy conservation.

Connecting magnetic and electric field reasoning

Unit 12 questions often require you to combine concepts from Units 10 and 11 with magnetism. Velocity selector problems require balancing electric force qE against magnetic force qvB. Hall effect problems connect charge carrier density to a measurable voltage. Circular motion problems require setting the magnetic force equal to the centripetal force expression mv^2/r. Showing the reasoning chain clearly, not just the final answer, is essential in free-response scoring.

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Topic study guides

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FRQ practice

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Cram archive videos

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Official unit cheatsheet

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Frequently Asked Questions

What's on the AP Physics 2 Unit 12 progress check (MCQ and FRQ)?

The AP Physics 2 Unit 12 progress check includes both MCQ and FRQ parts drawn from all four unit topics: magnetic fields and force on a moving charge, magnetism and moving charges, magnetism and current-carrying wires, and electromagnetic induction. The MCQ part tests conceptual reasoning and quantitative skills, while the FRQ part typically asks you to analyze scenarios involving magnetic forces or induced EMF. For matched practice that mirrors the progress check format, visit /ap-physics-2-revised/unit-12.

How do I practice AP Physics 2 Unit 12 FRQs?

The best way to practice AP Physics 2 Unit 12 FRQs is to focus on the two highest-yield topics: electromagnetic induction (Topic 12.4) and magnetic fields and force on a moving charge (Topic 12.1). Free-response questions in this unit typically ask you to derive or apply the force on a charged particle, explain how changing magnetic flux induces an EMF, or analyze a circuit with an induced current. Practice by writing out full solutions, showing your reasoning with diagrams, and checking that your units and sign conventions are correct. Find Unit 12 FRQ practice at /ap-physics-2-revised/unit-12.

Where can I find AP Physics 2 Unit 12 practice questions?

For AP Physics 2 Unit 12 practice questions, including multiple-choice and practice test sets covering magnetic fields, moving charges, current-carrying wires, and electromagnetic induction, head to /ap-physics-2-revised/unit-12. That page collects MCQ drills and full practice tests aligned to the 12-15% exam weight of this unit, so you can target exactly the concepts that show up most on the AP exam.

How should I study AP Physics 2 Unit 12?

Start by building a solid picture of how magnetic fields are created and how they exert forces on moving charges, since Topics 12.1 and 12.2 form the foundation everything else rests on. Then work through Topic 12.3 on current-carrying wires, paying close attention to the right-hand rule and how wire geometry affects field direction. Save dedicated time for Topic 12.4 on electromagnetic induction, which is the most FRQ-heavy topic in the unit. Draw diagrams for every problem, practice converting between field, force, and flux relationships, and do timed MCQ sets to build the quick conceptual recall the exam rewards. All four topics are organized at /ap-physics-2-revised/unit-12.

Ready to review Unit 12?Start with the notes, check the topic cards, and use the practice or resource links when they are available for this course.

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AP Physics 2 Unit 12 Review: Magnetism and Electromagnetism

AP Physics 2 unit 12 topics

Magnetic Fields

Magnetism and Moving Charges

Magnetism and Current-Carrying Wires

Electromagnetic Induction and Faraday's Law

Practice AP Physics 2 unit 12 questions

Example stimulus-based MCQs

Stimulus-based practice question

Stimulus-based practice question

Example FRQs

Magnetic force on charged particle in solenoid

Magnetic forces on moving charge near wire

Magnetic force on moving charge near current-carrying wire

AP Physics 2 unit 12 practice test

Unit 12 review notes

Magnetic Fields and Material Behavior

Magnetic Force on Moving Charges

Magnetic Fields and Forces from Current-Carrying Wires

Electroma­gnetic Induction and Faraday's Law

Key terms

How to review unit 12

Topics students miss most

Common unit 12 mistakes

Confusing magnetic force direction for negative charges

Thinking magnetic force does work

Misidentifying what angle to use in flux and force equations

Applying Lenz's law in the wrong direction

Forgetting that the magnetic field from a wire decreases as 1/r, not 1/r^2

How this unit shows up on the AP exam

Predicting force direction and magnitude from field diagrams

Reasoning about electromagnetic induction scenarios

Connecting magnetic and electric field reasoning

More ways to review

Topic study guides

Practice questions

FRQ practice

Cram archive videos

Official unit cheatsheet

Score calculator

Unit 12 printables

Frequently Asked Questions

What's on the AP Physics 2 Unit 12 progress check (MCQ and FRQ)?

How do I practice AP Physics 2 Unit 12 FRQs?

Where can I find AP Physics 2 Unit 12 practice questions?

How should I study AP Physics 2 Unit 12?

Electromagnetic Induction and Faraday's Law