Force in Electric Field Calculator
Force experienced by a charge in a field.
Formula first
Overview
This equation defines the electrostatic force exerted on a point charge when placed within an external electric field. It illustrates that the force is directly proportional to both the magnitude of the charge and the intensity of the field, acting parallel to field lines for positive charges and anti-parallel for negative charges.
Symbols
Variables
F = Force, E = Field Strength, q = Charge
Apply it well
When To Use
When to use: Use this equation when dealing with a point charge interacting with a known external electric field. It is applicable in scenarios involving uniform fields, such as those between parallel plates, or non-uniform fields where the field value at a specific point is known.
Why it matters: It is the fundamental principle behind particle accelerators, cathode ray tubes, and the operation of inkjet printers. Understanding this relationship allows engineers to precisely control the trajectory of charged particles in medical imaging and semiconductor manufacturing.
Avoid these traps
Common Mistakes
- Using E in V/m instead of N/C (they are equivalent).
- Forgetting sign for negative charges.
One free problem
Practice Problem
A proton with a charge of 1.6 × 10⁻¹⁹ C is placed in a uniform electric field with a strength of 450 N/C. What is the magnitude of the electric force acting on the proton?
Solve for:
Hint: Multiply the charge of the proton by the electric field strength.
The full worked solution stays in the interactive walkthrough.
References
Sources
- Halliday, Resnick, Walker, Fundamentals of Physics
- Griffiths, Introduction to Electrodynamics
- Wikipedia: Electric field
- Halliday, Resnick, Walker - Fundamentals of Physics, 11th Edition
- NIST Special Publication 330 (2019) - The International System of Units (SI)
- Halliday, Resnick, and Walker Fundamentals of Physics, 11th ed.
- Griffiths Introduction to Electrodynamics, 4th ed.
- Wikipedia: Electric field (article title)