Magnetic Field & Charged Particle Motion – AP Physics 2 | ShowMeClass

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Magnetic Field & Charged Particle

AP Physics 2 · Unit 5: Magnetism

Learning Objectives

Apply the magnetic force law: F = qv × B

Explain why B force does no work on charged particles

Calculate the radius of circular orbit: r = mv/(qB)

Use the right-hand rule for force direction

Key Equations

Right-Hand Rule

For +q: Point fingers along v, curl toward B. Thumb = F.

For −q: Use left hand, or reverse the result.

B into page = ⊗ (crosses)
B out of page = ⊙ (dots)

Particle Colors

Proton / positive charge

Electron / negative charge

B-field region

Lorentz ForceCyclotronB-FieldAP Physics 2

r =—

T =—

f =—

|F| =—

Particle

B Field (T) 0.5

B Direction

Speed (×10⁶ m/s) 2.0

Launch Angle (°) 0

Speed Multiplier 1×

Display

Orbit Parameters

📝 Quick Quiz▼

1. The magnetic force on a charged particle is always:

Parallel to velocity Perpendicular to velocity Opposite to velocity Along B

2. A magnetic force does _____ work on a moving charge:

Positive Negative Zero Variable

3. If a proton's speed doubles, its circular orbit radius:

Halves Doubles Quadruples Stays the same