Electric Field Calculator
Calculate electric field strength from point charges using Coulomb's law and electrostatic principles
Calculate Electric Field
Point charge generating the electric field
Distance from charge to field measurement point
1.0 for vacuum/air, higher for other materials
Select desired unit for electric field output
Electric Field Results
Field Strength Analysis
Example Calculation
Electron at Atomic Scale
Charge: 1 elementary charge (e)
Distance: 0.5 nm (atomic scale)
Medium: Vacuum (εᵣ = 1)
Calculation
E = k|q|/r²
E = (8.988 × 10⁹) × (1.602 × 10⁻¹⁹) / (0.5 × 10⁻⁹)²
E = 5.76 × 10¹¹ N/C
Key Formulas
E = k|Q|/r²
Electric field from point charge
k = 8.988 × 10⁹ N⋅m²/C²
F = qE
Force on charge in electric field
F is force, q is test charge
E = V/d
Uniform field between plates
V is potential difference
Physical Constants
Understanding Electric Fields
What is an Electric Field?
An electric field is a region around charged particles where electric forces can be detected. It's a vector field that describes the electric force per unit charge that would be exerted on a small positive test charge placed at any point in space.
Field Direction and Properties
- •Positive charges: Field lines point radially outward
- •Negative charges: Field lines point radially inward
- •Field strength: Inversely proportional to distance squared
- •Units: N/C (force per unit charge) or V/m (voltage gradient)
Mathematical Foundation
E = k|Q|/(εᵣr²)
Electric field from a point charge
Note: Electric field is a vector quantity. For multiple charges, vector addition is required to find the net field at any point.
Atomic Scale
At atomic distances (nanometers), electric fields are extremely strong, often exceeding 10¹¹ N/C. These fields hold electrons in orbit around nuclei.
Everyday Applications
Electric fields are used in CRT displays, particle accelerators, photocopiers, and air purification systems. Typical strengths range from 10³ to 10⁶ N/C.
Safety Considerations
Air breaks down at ~3 × 10⁶ V/m, creating sparks or lightning. High-voltage equipment must be designed to avoid exceeding this threshold.