AP Physics 2 Flashcards: Magnetism And Moving Charges

What this deck covers

This deck focuses on Magnetism And Moving Charges, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 2.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the formula for the magnetic force on a moving charge?

Answer: $F = qvB \, \sin(\theta)$. Force depends on charge, velocity, field strength, and angle between $v$ and $B$.

Flashcard 2: What is the value of $\mu_0$, the permeability of free space?

Answer: $4\pi \times 10^{-7} \, T\cdot m/A$. Fundamental physical constant used in magnetic field calculations.

Flashcard 3: Identify the symbol for magnetic permeability of free space.

Answer: $\mu_0$. Fundamental constant relating current to magnetic field in vacuum.

Flashcard 4: What is the effect of a magnetic field on a loop of current?

Answer: Torque acts on the loop. Current loop behaves like magnetic dipole in external field.

Flashcard 5: What is the effect of a magnetic field on a stationary charge?

Answer: No force is exerted. Magnetic force requires motion; stationary charges are unaffected.

Flashcard 6: What is the relationship between electric and magnetic fields in electromagnetic waves?

Answer: Perpendicular to each other. EM waves consist of oscillating $E$ and $B$ fields at right angles.

Flashcard 7: State the right-hand rule for the direction of magnetic force.

Answer: Thumb: velocity, Fingers: field, Palm: force. Use right hand to determine force direction on positive charges.

Flashcard 8: What is the force between two parallel current-carrying wires?

Answer: Attractive if currents are in the same direction. Parallel currents attract; antiparallel currents repel each other.

Flashcard 9: What does Lenz's Law state about electromagnetic induction?

Answer: Induced current opposes the change causing it. Nature opposes changes in magnetic flux through circuits.

Flashcard 10: State the formula for the magnetic field inside a solenoid.

Answer: $B = \mu_0 n I$. Field strength proportional to current and turns per unit length.

Flashcard 11: State the right-hand rule for the direction of magnetic force.

Answer: Thumb: velocity, Fingers: field, Palm: force. Use right hand to determine force direction on positive charges.

Flashcard 12: Define the term 'magnetic dipole moment'.

Answer: Measure of the strength of a magnetic source. Quantifies the magnetic field strength produced by a current distribution.

Flashcard 13: Identify the unit of magnetic flux.

Answer: Weber (Wb). Named after Wilhelm Weber; unit of magnetic flux linkage.

Flashcard 14: What is the effect of a magnetic field on a stationary charge?

Answer: No force is exerted. Magnetic force requires motion; stationary charges are unaffected.

Flashcard 15: What is the relationship between electric and magnetic fields in electromagnetic waves?

Answer: Perpendicular to each other. EM waves consist of oscillating $E$ and $B$ fields at right angles.

Flashcard 16: Calculate the magnetic force on a $3m$ wire carrying $5A$ in a $0.2T$ field.

Answer: $3 \, N$. Using $F = ILB$: $5 \times 3 \times 0.2 = 3N$.

Flashcard 17: What is the direction of the magnetic field around a current-carrying wire?

Answer: Circular around the wire. Right-hand rule: thumb along current, fingers curl with field.

Flashcard 18: State the formula for the magnetic field of a circular loop at its center.

Answer: $B = \frac{\mu_0 I}{2R}$. Field at center is half that of an infinite straight wire.

Flashcard 19: State the Biot-Savart Law for the magnetic field due to a current element.

Answer: $dB = \frac{\mu_0 I dl \sin(\theta)}{4\pi r^2}$. Fundamental law relating current elements to magnetic field production.

Flashcard 20: Identify the direction of the magnetic force on a negative charge.

Answer: Opposite to the right-hand rule direction. Negative charges experience force opposite to positive charge direction.

Flashcard 21: Define Ampère's Law.

Answer: Line integral of $B$ around a closed path equals $\mu_0 I$. Relates magnetic field circulation to enclosed current.

Flashcard 22: Calculate the magnetic field at a point $5cm$ from a wire carrying $6A$ current.

Answer: $2.4 \times 10^{-5} \, T$. Using $B = \frac{\mu_0 I}{2\pi r}$ with given values.

Flashcard 23: What is the path of a charged particle in a uniform magnetic field?

Answer: Circular or helical. Magnetic force provides centripetal acceleration for curved motion.

Flashcard 24: State the formula for the magnetic field of a circular loop at its center.

Answer: $B = \frac{\mu_0 I}{2R}$. Field at center is half that of an infinite straight wire.

Flashcard 25: State the effect of a uniform magnetic field on the speed of a charged particle.

Answer: Speed remains constant. Magnetic force is perpendicular to velocity, doing no work.

Flashcard 26: What does a solenoid generate when a current flows through it?

Answer: Uniform magnetic field inside. Coil of wire creates strong, uniform field along its axis.

Flashcard 27: What is the formula for the Lorentz force?

Answer: $F = q(E + v \times B)$. Combines electric and magnetic forces on a moving charge.

Flashcard 28: Find the magnetic force on a $2C$ charge moving at $3m/s$ in a $4T$ field at $90^{\circ}$.

Answer: $24 \, N$. Using $F = qvB$: $2 \times 3 \times 4 = 24N$ at maximum angle.

Flashcard 29: Calculate the magnetic force on a $0.5C$ charge at rest in a $2T$ field.

Answer: $0 \, N$. No velocity means no magnetic force on the charge.

Flashcard 30: Define Ampère's Law.

Answer: Line integral of $B$ around a closed path equals $\mu_0 I$. Relates magnetic field circulation to enclosed current.

Flashcard 31: What is the magnetic moment of a loop of current?

Answer: $\mu = I \cdot A$. Product of current and loop area defines magnetic strength.

Flashcard 32: Identify the unit of magnetic flux.

Answer: Weber (Wb). Named after Wilhelm Weber; unit of magnetic flux linkage.

Flashcard 33: What is the formula for magnetic flux?

Answer: $\Phi = B \cdot A \cdot \cos(\theta)$. Flux depends on field strength, area, and angle between them.

Flashcard 34: What is the Hall effect?

Answer: Voltage developed across a conductor in a magnetic field. Moving charges in magnetic field separate, creating potential difference.

Flashcard 35: Calculate the magnetic field at a point $5cm$ from a wire carrying $6A$ current.

Answer: $2.4 \times 10^{-5} \, T$. Using $B = \frac{\mu_0 I}{2\pi r}$ with given values.

Flashcard 36: What does Lenz's Law state about electromagnetic induction?

Answer: Induced current opposes the change causing it. Nature opposes changes in magnetic flux through circuits.

Flashcard 37: Identify the direction of the magnetic moment vector of a current loop.

Answer: Perpendicular to the plane of the loop. Vector points normal to loop plane using right-hand rule.

Flashcard 38: State the relationship between current and magnetic field in a solenoid.

Answer: Directly proportional. More current produces stronger magnetic field inside solenoid.

Flashcard 39: Identify the direction of the magnetic force on a negative charge.

Answer: Opposite to the right-hand rule direction. Negative charges experience force opposite to positive charge direction.

Flashcard 40: Calculate the magnetic force on a $0.5C$ charge at rest in a $2T$ field.

Answer: $0 \, N$. No velocity means no magnetic force on the charge.

Flashcard 41: What is the formula for the Lorentz force?

Answer: $F = q(E + v \times B)$. Combines electric and magnetic forces on a moving charge.

Flashcard 42: State the relationship between current and magnetic field in a solenoid.

Answer: Directly proportional. More current produces stronger magnetic field inside solenoid.

Flashcard 43: Define the unit of magnetic field strength.

Answer: Tesla (T). Named after Nikola Tesla; measures magnetic field intensity.

Flashcard 44: State the effect of a uniform magnetic field on the speed of a charged particle.

Answer: Speed remains constant. Magnetic force is perpendicular to velocity, doing no work.

Flashcard 45: What is the SI unit for electric charge?

Answer: Coulomb (C). Fundamental unit for quantifying electric charge in physics.

Flashcard 46: Identify the direction of the magnetic moment vector of a current loop.

Answer: Perpendicular to the plane of the loop. Vector points normal to loop plane using right-hand rule.

Flashcard 47: What is the magnetic field formula for a long straight wire?

Answer: $B = \frac{\mu_0 I}{2\pi r}$. Field strength decreases with distance; circular field lines around wire.

Flashcard 48: What is the path of a charged particle in a uniform magnetic field?

Answer: Circular or helical. Magnetic force provides centripetal acceleration for curved motion.

Flashcard 49: What is the force between two parallel current-carrying wires?

Answer: Attractive if currents are in the same direction. Parallel currents attract; antiparallel currents repel each other.

Flashcard 50: What is the Hall effect?

Answer: Voltage developed across a conductor in a magnetic field. Moving charges in magnetic field separate, creating potential difference.

Flashcard 51: What is the direction of the magnetic field inside a solenoid?

Answer: Parallel to the axis of the solenoid. Field lines run straight through the solenoid's center.

Flashcard 52: Calculate the magnetic force on a $3m$ wire carrying $5A$ in a $0.2T$ field.

Answer: $3 \, N$. Using $F = ILB$: $5 \times 3 \times 0.2 = 3N$.

Flashcard 53: Define the term 'magnetic flux'.

Answer: Product of magnetic field and area normal to it. Measures how much magnetic field passes through a surface.

Flashcard 54: State the formula for the magnetic force on a current-carrying wire.

Answer: $F = ILB \sin(\theta)$. Force on wire depends on current, length, field, and orientation angle.

Flashcard 55: State the formula for the magnetic force on a current-carrying wire.

Answer: $F = ILB \sin(\theta)$. Force on wire depends on current, length, field, and orientation angle.

Flashcard 56: What is the value of $\mu_0$, the permeability of free space?

Answer: $4\pi \times 10^{-7} \, T\cdot m/A$. Fundamental physical constant used in magnetic field calculations.

Flashcard 57: What is the SI unit for electric charge?

Answer: Coulomb (C). Fundamental unit for quantifying electric charge in physics.

Flashcard 58: Define the term 'magnetic flux'.

Answer: Product of magnetic field and area normal to it. Measures how much magnetic field passes through a surface.

Flashcard 59: What is the direction of the magnetic field around a current-carrying wire?

Answer: Circular around the wire. Right-hand rule: thumb along current, fingers curl with field.

Flashcard 60: State the Biot-Savart Law for the magnetic field due to a current element.

Answer: $dB = \frac{\mu_0 I dl \sin(\theta)}{4\pi r^2}$. Fundamental law relating current elements to magnetic field production.

Flashcard 61: Identify the condition for maximum magnetic force on a charge.

Answer: $\theta = 90^{\circ}$. Perpendicular alignment gives maximum $\sin(\theta) = 1$.

Flashcard 62: What is the formula for the magnetic force on a moving charge?

Answer: $F = qvB \, \sin(\theta)$. Force depends on charge, velocity, field strength, and angle between $v$ and $B$.

Flashcard 63: What is the magnetic moment of a loop of current?

Answer: $\mu = I \cdot A$. Product of current and loop area defines magnetic strength.

Flashcard 64: Identify the condition for maximum magnetic force on a charge.

Answer: $\theta = 90^{\circ}$. Perpendicular alignment gives maximum $\sin(\theta) = 1$.

Flashcard 65: What is the magnetic field formula for a long straight wire?

Answer: $B = \frac{\mu_0 I}{2\pi r}$. Field strength decreases with distance; circular field lines around wire.

Flashcard 66: What is the effect of a magnetic field on a loop of current?

Answer: Torque acts on the loop. Current loop behaves like magnetic dipole in external field.

Flashcard 67: What is the formula for magnetic flux?

Answer: $\Phi = B \cdot A \cdot \cos(\theta)$. Flux depends on field strength, area, and angle between them.

Flashcard 68: Define the term 'magnetic dipole moment'.

Answer: Measure of the strength of a magnetic source. Quantifies the magnetic field strength produced by a current distribution.

Flashcard 69: Find the magnetic force on a $2C$ charge moving at $3m/s$ in a $4T$ field at $90^{\circ}$.

Answer: $24 \, N$. Using $F = qvB$: $2 \times 3 \times 4 = 24N$ at maximum angle.