Which term denotes the oscillation frequency of a system when damping is zero?

• A. Normal Frequency (Wo)
• B. Damping Factor
• C. Rise Time
• D. Peak Time

Answer: (A)

The oscillation frequency when damping is zero is the natural (undamped) frequency. This is the rate at which the system freely vibrates without energy loss. For a simple mass-spring, it’s given by ω_n = sqrt(k/m), representing the angular frequency of the undamped motion. As damping disappears, the frequency of the actual (damped) oscillations approaches this natural frequency, so ω_d → ω_n. Among the options, this concept is captured by Normal Frequency (Wo), which denotes the natural/undamped frequency. The other terms describe how quickly the motion dies out (Damping Factor) or time-domain response measures like Rise Time and Peak Time, not the intrinsic frequency.