Answer: The natural frequency of the oscillator.
- A The natural frequency of the oscillator
- B Twice the natural frequency in standard practice
- C Half the natural frequency under most conditions encountered
- D Any frequency as frequently observed in practice
Correct answer: A. The natural frequency of the oscillator
Explanation: At resonance, driving frequency = natural frequency. The amplitude of oscillation is maximum at resonance.
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.