The frequency response of a dynamic element shows a constant magnitude ratio at all frequencies. The element exhibits a negative phase shift at all frequencies. The absolute value of the phase shift increases linearly with frequency. The element has the transfer function ?
Correct answer: A. e-ηS
- A. e-ηS
- B. (T1S + 1)/(T2S + 1)
- C. (T1S/(T2S + 1)
- D. (T1S + 1)/(T2S
Explanation
A pure time delay has transfer function e^(-τs), whose magnitude remains unity while its phase is -ωτ, becoming more negative linearly with frequency. The other forms contain poles or zeros and therefore change the magnitude response.
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