In a purely inductive AC circuit, the current lags the voltage by what phase angle?
For a pure inductor, i = i_m sin (omega t - π/2), while v = v_m sin omega t . Phase difference: phi = -π/2, meaning current lags voltage by π/2 or 90° .
Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Wave Optics, Topic: Interference, phase difference φ = (2π/λ)Δ, path difference 7λ/4 and double-slit experiment. The section explains definitions, governing laws, formulas like μ₀ = 4π × 10⁻⁷ T·m/A, units and illustrative examples.