Electricity & Magnetism
Electrostatics, current electricity, magnetic fields, Lorentz force, and electromagnetic induction.
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Electric Charge and Field
Khan Academy
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Gauss's Law
Professor Dave Explains
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Ohm's Law and Circuits
Michel van Biezen
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RC Circuits
Khan Academy
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Magnetic Force on Moving Charge
Professor Dave Explains
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Faraday's Law
Khan Academy
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Notes
Electrostatics
- Coulomb's law: F = k q₁q₂ / r².
- Electric field E = F/q; for point charge E = kq/r².
- Potential V = kq/r; E = −∇V.
- Capacitance C = Q/V; energy = ½CV².
F = k q₁q₂/r²
E = kq/r²
C = Q/V
U = ½CV²
Current Electricity & RC
- Ohm's law: V = IR; power P = IV = I²R.
- Kirchhoff: ΣV = 0 (loop), ΣI = 0 (junction).
- RC charging: V = V₀(1 − e^{−t/RC}); τ = RC.
V = IR
P = I²R
V_C = V₀(1 − e^{−t/RC})
Magnetism & Induction
- Lorentz force: F = q(v × B); circular motion r = mv/(|q|B).
- Faraday: ε = −dΦ_B/dt; Lenz's law gives direction.
- Transformers: V_s/V_p = N_s/N_p (ideal).
F = q v B sinθ
r = mv/(|q|B)
ε = −dΦ/dt
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