🚫 Force vs Field Confusion
❌ "Electric field is the force on a charge"
✓ E = F/q — field is force per unit charge. E exists even with no test charge present!
Fix: Always ask "force on what?" before writing the formula.
🚫 Gauss's Law Trap
❌ "Bigger Gaussian surface = more flux"
✓ Φ = q_enclosed/ε₀ — flux depends ONLY on enclosed charge, not surface size or shape
Fix: Draw the Gaussian surface and ONLY count charges inside it.
🚫 Dipole Moment Direction
❌ "Dipole moment points from + to −"
✓ p points from −q to +q (negative to positive). Opposite to the field direction between plates!
Fix: Remember "p points to positive" as a mnemonic.
🚫 Field Inside Conductor
❌ "E inside a charged conducting sphere = kQ/r²"
✓ E = 0 ALWAYS inside a conductor in electrostatic equilibrium. No exceptions!
Fix: Remember "conductor = E zero inside" as absolute rule.
🚫 Inverse Square Mistake
❌ "Double the distance → force halves"
✓ F ∝ 1/r² → Double distance → Force becomes ¼ (not ½!)
Fix: Write "r²" three times before doing any calculation.
🚫 Field Lines Form Loops
❌ "Electric field lines form closed loops"
✓ Only MAGNETIC field lines are closed loops. Electric field lines start on + and end on −.
Fix: Electric = open lines. Magnetic = closed loops. Never mix these up!
🚫 Superposition Scalar Sum
❌ Adding force magnitudes directly without considering directions
✓ Forces are vectors — resolve into x, y components, add algebraically, then find resultant magnitude
Fix: Always draw the force diagram first. Never add magnitudes without checking if they're parallel.
🚫 Dipole Equilibrium
❌ "θ = 90° is stable equilibrium (max torque)"
✓ θ = 0° is STABLE (min PE). θ = 180° is UNSTABLE. θ = 90° gives max torque but is NOT equilibrium!
Fix: Stable = dipole aligned with field (θ=0°). Torque tries to bring it there.