A. Explain the two reasons why adaptive controllers are needed in chemieal processes. [] B. Consider a process with the following transfer fimetions for its primary and secondary elements, Gp,1=((0.5s+1)(s+1)1)andGp,n=(0.1s+11) The secondary process is faster than the primary, use the open-loop transfer with Pl control (y=1). Calculate: i. cross-over frequency ii. ultimate gain for a simple feedback control [8] [6] iii. explain how you can also find the same values for a cascade control [5] tan1(acos1)+tan10.10cos0+tan10.5sacco+tan1axco180