Answer: Driving frequency approaches the natural frequency.
- A Driving frequency approaches the natural frequency
- B Damping is maximum
- C Driving frequency is twice the natural frequency
- D Damping coefficient is zero
Correct answer: A. Driving frequency approaches the natural frequency
Explanation: Maximum amplitude (resonance) occurs when driving frequency is close to the natural frequency. Higher damping reduces and broadens the resonance peak.
In SHM, displacement and velocity are 90° out of phase (v is maximum when x=0, and zero when x is extreme), while acceleration is always exactly opposite in sign to displacement, consistent with a = −ω²x.
Concept context
Simple harmonic motion, spring-mass, pendulum, energy in SHM, and resonance.