Electric Potential & Equipotential Lines – AP Physics 2 | ShowMeClass

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Electric Potential & Equipotentials

AP Physics 2 · Unit 3: Electric Forces & Fields

Learning Objectives

Calculate V from point charges: V = kq/r

Draw equipotential lines (V = constant)

Explain why E ⊥ equipotential surfaces

Relate ΔV to work: W = −qΔV

Key Equations

Color Map

V < 0V = 0V > 0

Equipotential contours

E-field lines (⊥ to contours)

Key Concepts

V is scalar — add potentials algebraically, no vectors needed.
No work is done moving a charge along an equipotential.
E points from high V to low V (steepest descent).
Closer contours → stronger E.

PotentialEquipotentialE-FieldAP Physics 2

Charges—

Contours—

Click anywhere to probe V and E at that point. Drag charges to reposition.

Preset Configurations

|Charge| (μC) 1.0

Contour Levels 12

Display

Potential Probe

Click on the canvas to measure V and E at any point.

📝 Quick Quiz▼

1. Electric potential V is a:

Vector quantity Scalar quantity Dimensionless number Force

2. Work done moving a charge along an equipotential is:

Maximum Dependent on path Zero Negative

3. E-field lines are always _____ to equipotential surfaces:

Parallel Perpendicular At 45° Tangent