Apropeller is operating initially at j = 1.0. for the blade section at 70 percent of the maximum radius, find the value of the advance ratio where the angle of attack is reduced by 5 degrees.

Which of the following ziegler nichols tuning methods the response of the controller to a step input should exhibit an s-shaped curve? a)-open loop mode b)-closed loop mode c)-both modes (open & closed) d)-none of the modes (open & closed)