Which of the following periodic motions cannot be classified as oscillatory due to the absence of a fixed equilibrium po
**Forced oscillations** result when external periodic driving force F = F₀ cos(ω_d t) acts on oscillator, steady-state frequency equals driving frequency ω_d, amplitude A = F₀/√((k - m ω_d²)² + (b ω_d)²) depends on proximity to natural frequency ω₀ = √(k/m). Resonance when ω_d ≈ ω₀, amplitude maximum. Rotational motion of a ceiling fan is periodic but not oscillatory, as it lacks a fixed equilibrium point about which it moves to-and-fro, unlike SHM examples. Applying x = A cos(ωt + φ), v = -ωA sin(ωt + φ), a = -ω²x and E = ½kA² = ½mω²A², result Rotational motion of a ceiling fan follows, reflecting
Ref: NCERT > Physics Book > Oscillations > Forced Oscillations and Resonance