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  1. The Nyquist locus of a transfer function
    G(s) H(s) =
    K
    1 + sT1

    in given below in figure The locus is modified as shown below in figure, on addition of poles to the original G (s) H (s). Then, the transfer function of the modified locus is—


    1. G(s) H(s) =
      K
      s(1 + sT1)
    2. G(s) H(s) =
      K
      (1 + sT1)(1 + sT2)
    3. G(s) H(s) =
      K
      s(1 + sT1)(1 + sT2)

    4. G(s) H(s) =
      K
      s(1 + sT1)(1 + sT2)(1 + sT3)
Correct Option: B

From the given Nyquist plot we conclude that both the Nyquist plot have phase = 0° at ω = 0.
and it can be possible only from the modified transfer function given in option (B) only.
Hence alternative (B) is the correct choice



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