Recent questions in Instrumentation and Process Control

The liquid flow rate through an equal percentage control valve, when fully open, is $150$ gal/min and the corresponding pressure drop is $50$ psi. If the specific gravity...

Consider two non-interacting tanks-in-series as shown in figure. Water enters $TANK$ $1$ at $q$ $cm^{3}/s$ and drains down to $TANK$ $2$ by gravity at a rate $k\sqrt{h_{1...

Choose the option that correctly matches the step response curve on the left with the appropriate transfer functions on the right. The step input change occurs at time $t...

For the closed loop system shown in figure, the phase margin (in degrees) is ____________ (rounded off to one decimal place).

Match the variable in Group-$1$ with the instruments in Group-$2$.$\begin{array}{cc}\&\text{Group-$1$} & \text{Group-$2$} \\ &\text{P. Temperature} & \text{ I. Capacitanc...

An $LVDT$ (Linear Variable Differential Transformation) is a transducer used for convertingdisplacement to voltagevoltage to displacementresistance to voltagevoltage to c...

The transfer function of a system is$$\frac{1}{4s^{2}+1.2s+1}$$For a unit step increase in the input, the fractional overshoot, rounded to $2$ decimal place, is _________...

The open loop transfer function of a process with a proportional controller (gain $K_{C}$) is$$G_{OL}=K_{C}\frac{e^{-2s}}{s}$$Based on the Bode criterion for closed-loop ...

The characteristics equation of a closed-loop system is$$6s^{3}+11s^{2}+6s+\left ( 1+K \right )=0,\:\:\:\:\:\: where \:K>0$$The value of $K$ beyond which the system just ...

Match the instruments in $Group–I$ with process variable in $Group–2$.$\begin{array}{cc}\\&\text{Group-1} & \text{Group-2} \\ &\text{P. Conductivity meter} & \text{ I. Fl...

What is the order of response exhibited by a $U$-tube manometer? Zero orderFirst orderSecond orderThird order

A system exhibits inverse response for a unit step change in the input. Which one of the following statement must necessarily be satisfied?The transfer function of the sy...

A liquid flows through an “equal percentage” valve at a rate of $2\:m^{3}/h$ when the valve is $10\%$ open. When the valve opens to $20\%$ the flowrate increases to $3\:m...

A $PI$ controller with integral time constant of $0.1$ min is to be designed to control a process with transfer function$$G_{P}\left ( s \right )=\frac{10}{s^{2}+2s+100}$...

For a unit step input, the response of a second order system is$$y\left ( t \right )=K_{p} \left [ 1-\frac{1}{\sqrt{1-\zeta ^{2}}} e^{\frac{\zeta t}{\tau }}\sin\left ( \f...

Match the output signals as obtained from four measuring devices in response to a unit step change in the input signal.$\begin{array}{cc}\&\text{P. Gas chromatograph, wit...

The transfer function for the disturbance response in an open-loop process is given by $G_{d}^{open}(s)$. The corresponding transfer function for the disturbance response...

Which one of the following transfer functions, upon a unit step change in disturbance at $t=0$, will show a stable time domain response with a negative initial slope (i.e...

The block diagram for a process with feedback control for output deviation $h$ is shown in the figure below. All transfer functions are given with pre-factor of $s$ in mi...

Consider a control system with the open loop transfer function given by :$G_{OL}\left ( s \right )=\frac{K_{c}e^{-0.3z}}{1.5s+1}$In the above function, pre-factor of $s$ ...

Consider the following block diagram for a closed-loop feedback control system A proportional controller is being used with $K_{c}=-4$. If a step change in distrubance of...

A process with transfer function, $G_{p}=\frac{2}{s-1}$ is to be controlled by a feedback proportional controller with a gain $K_{c}$. If the transfer functions of all ot...

Given below is a simplified block diagram of a feedforward control system.The transfer function of the process is $G_{p}=\frac{5}{s+1}$ and the disturbance transfer funct...

A step change of magnitude $2$ is introduced into a system having the following transfer function$$G\left ( s \right )=\frac{2}{s^{2}+2s+4}$$The percent overshoot is ____...

Assume that an ordinary mercury-in-glass thermometer follows first order dynamics with a time constant of $10\:s$. It is at a steady state temperature of $0^{\circ}C$. At...

A unit $IMPLUSE$ response of a first order system with time constant $\tau$ and steady state gain $K_{p}$ is given by $\frac{1}{K_{p}\tau }e^{t/\tau }$$K_{p}e^{-t/\tau}$...

For the computation of Ziegler-Nichols settings, the ultimate period (in s/cycle) and the ultimate gain are $\pi$ and $0.8$, respectively$4\pi$ and $0.8$, respectively$4\...

Consider the following transfer function $G_p(s) = \dfrac{5}{(2s+1)^4}$(Note: The unit of the processor time constan...

A control value, with a turndown ratio of 50, follows equal percentage characteristics. The flow rate of a liquid through the value at 40% stem positions is 1 m$^{3}$/h. ...

A unit gain 2$^{nd}$ order underdamped process has a period of oscillation 1 second and decay ratio 0.25. The transfer function of the process is$\frac{1}{0.024s^2 + 0.06...

Match the following$\bf{Group 1}$ $\bf{Group 2}$(P) Viscosity (1) Pyrometer(Q) Pressure ...

The block diagram of a system with a proportional controller is shown below A unit step is introduced in the set point. Th...

The characteristic equation for a system is $S^{3}+9S^{2}+26S+12(2+K{_c}) = 0$.Using the Routh test, the value of $K{_...

A thermocouple having a linear relationship between $0\;^{\circ}C$ and $350 \:^{\circ}C$ shows an emf of zero and $30.5 \text{ mV}$, respectively at these two temperature...

The Bode stability criterion is applicable whenGain and phase curves decrease continuously with frequencyGain curve increase and phase curve decreases with frequencyGain ...

For a closed-loop system, consider the following transfer functions:process $G_{p}\left ( s \right )$, controller $G_{c}\left ( s \right )$, measuring device $G_{m}\left ...

Consider the following transfer function:$$G\left ( s \right )=\frac{3}{\left ( 5s+1 \right )^{2}}$$where, the natural period of oscillation is in min. The amplitude rati...

Match the items in Column $A$ with the items in Column $B$$\begin{array}{|cl|cI|}\hline&\text{$Column\:A$} & \text{$Column\:A$} \\ \hline &\text{P. Pure dead-time} & \te...

A first-order process having a transfer function, $G_{p}=\frac{2}{7s+1}$ is controlled by a proportional controller with gain of $3.2$. The process time constant is in mi...