angela_wilson
angela_wilson Feb 23, 2026 β€’ 0 views

Electric Potential due to a Point Charge Graphing: Potential vs Distance

Hey there! πŸ‘‹ Ever wondered how electric potential changes as you move away from a point charge? πŸ€” It's all about visualizing the relationship between potential and distance! Let's explore this with graphs and comparisons. Trust me, understanding this will make electrostatics way easier!
βš›οΈ Physics

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amber_carrillo Jan 4, 2026

πŸ“š Electric Potential due to a Point Charge

The electric potential, often denoted as $V$, at a distance $r$ from a point charge $q$ is given by the formula:

$\qquad V = \frac{kq}{r}$

where $k$ is Coulomb's constant ($k \approx 8.99 \times 10^9 \text{ N m}^2/\text{C}^2$). From this equation, we can see that the electric potential $V$ is inversely proportional to the distance $r$ from the point charge.

πŸ“ˆ Graphing Potential vs. Distance

When graphing electric potential ($V$) against distance ($r$) from a point charge, we observe a hyperbolic relationship. Here’s what you need to know:

  • πŸ“‰ Shape of the Graph: The graph is a hyperbola. As $r$ increases, $V$ decreases, approaching zero as $r$ approaches infinity.
  • πŸ“ Important Points: Close to the charge (small $r$), the potential $V$ is very large. As you move away (large $r$), the potential $V$ becomes smaller.
  • βž•/βž– Sign of the Charge: For a positive charge, the potential is positive; for a negative charge, the potential is negative. This affects which part of the hyperbola you see on the graph.

⚑ Electric Potential vs. Electric Field

It's important to distinguish between electric potential ($V$) and electric field ($E$). Here’s a comparison:

Feature Electric Potential ($V$) Electric Field ($E$)
Definition The electric potential energy per unit charge at a point in space. The force per unit charge experienced by a test charge at a point in space.
Nature Scalar quantity (magnitude only) Vector quantity (magnitude and direction)
Formula (Point Charge) $V = \frac{kq}{r}$ $E = \frac{kq}{r^2}$
Dependence on Distance Inversely proportional to distance ($V \propto \frac{1}{r}$) Inversely proportional to the square of the distance ($E \propto \frac{1}{r^2}$)
Graph (vs. Distance) Hyperbolic decay Quadratic decay

πŸ”‘ Key Takeaways

  • πŸ“ Inverse Relationship: Electric potential decreases as you move away from the charge.
  • πŸ“Š Graph Shape: The $V$ vs. $r$ graph is a hyperbola, reflecting the inverse relationship.
  • βž•/βž– Sign Matters: The sign of the charge determines the sign of the potential.
  • πŸ’‘ Scalar vs. Vector: Remember that potential is a scalar, while the electric field is a vector.

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