Electromagnetic Induction — Formula Sheet

Magnetic flux φ = B·A = BA cos θ, measured in Weber (Wb)

Symbol

L, Unit: Henry (H), where 1 H = 1 Wb/A = 1 V·s/A

For rotational motion

e = ½Bωl².

Defined as L = φ/i = Nφ/i for multi-turn coils.

Induced emf

e = -L(di/dt).

M = φ₁₂/i₂ = φ₂₁/i₁.

Coefficient of coupling

K = M/√(L₁L₂).