Arotary actuator has the following physical data: outer radius of rotor rr = 0.80 in outer radius of vane rv = 1.7 in width of vane l = 0. 5 in if the torque load is t = 900 in∙lb, what pressure p must be developed to overcome the load?

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)