Electric Field & Electric Field Intensity — A/L Physics

What must I remember about Electric Field & Electric Field Intensity?

• Electric Field (E): Force per unit positive test charge placed at that point: E = F / q0 (vector quantity, units N/C or V/m).
• Electric Field of a Point Charge: Radially outward for positive charge, radially inward for negative charge: E = (1 / (4πε0)) * (Q / r²).
• Electric Field Lines (Lines of Force): Imaginary continuous directed curves whose tangent at any point indicates the direction of E; originate on positive charges and terminate on negative charges; line density is proportional to magnitude |E|; lines NEVER intersect.
• Uniform Electric Field between Parallel Conducting Plates: E = V / d, where V is potential difference and d is plate separation; field lines are uniformly spaced and parallel.

Test yourself (1 minute)

1. Motion of Charged Particle in Uniform Electric Field

   Particle of mass m and charge q experiences constant acceleration a = q E / m; traverses parabolic trajectory analogous to projectile motion under gravity: x = v0 t, y = (1/2)(q E / m) t².

2. Conductor in Electrostatic Equilibrium

   1) E = 0 everywhere INSIDE the conductor bulk; 2) Excess charge resides strictly on external surface; 3) E at surface is PERPENDICULAR to surface with magnitude E = σ / ε0; 4) Entire conductor is an equipotential volume.

3. Action of Points (Corona Discharge)

   Charge density σ is highest at sharp points of small radius of curvature (σ ∝ 1/r); intense local electric field ionizes surrounding air molecules, producing electric wind; exploited in lightning conductors.

Practise Electric Field & Electric Field Intensity questions today

Source: NIE G.C.E. (A/L) Physics Resource Book - Unit 6: Electrostatic Field

What should I study first?

What comes next?

Next in the syllabus

Where does Electric Field & Electric Field Intensity fit in the syllabus?

Unit 6.2 · Year 1 · Term 3