List of top Instrumentation and Process Control Questions asked in GATE CH

Which of these symbols can be found in piping and instrumentation diagrams? 

The inherent characteristics of three control valves P, Q and R are shown in the figure. 

The CORRECT option(s) is/are 
 

A system has a transfer function
\[ G(s) = \frac{3e^{-4s}}{12s^2 + 1} \] When a step change of magnitude M is given to the system input, the final value of the system output is measured to be 120. The value of M is \(\underline{\hspace{1cm}}\) .
A process has a transfer function
\[ G(s) = \frac{Y(s)}{X(s)} = \frac{20}{90000s^2 + 240s + 1} \] Initially the process is at steady state with \( x(t = 0) = 0.4 \) and \( y(t = 0) = 100 \). If a step change in \( x \) is given from 0.4 to 0.5, the maximum value of \( y \) that will be observed before it reaches the new steady state is \(\underline{\hspace{1cm}}\) (round off to 1 decimal place).
Which of the following is NOT a necessary condition for a process under closed-loop control to be stable?
Which of the following is NOT a standard to transmit measurement and control signals?
A feedforward controller can be used only if: