MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 256 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The unit of ‘time constant’ of a system is the same as that of___________________? |
| A. | Velocity |
| B. | Time |
| C. | (Time)-1 |
| D. | None of these |
| Answer» C. (Time)-1 | |
| 52. |
The transfer function of a second order system is _____________________? |
| A. | 1/(T2s2 + 2ξTs + 1) |
| B. | 1/(T2s2 + 2Ts + 1) |
| C. | 1/(T2s2 + 2ξT + 1) |
| D. | None of these |
| Answer» B. 1/(T2s2 + 2Ts + 1) | |
| 53. |
The transfer function of a first order system is______________? |
| A. | 1/(Ts + 1) |
| B. | 1/Ts |
| C. | s/(Ts + 1) |
| D. | None of these |
| Answer» B. 1/Ts | |
| 54. |
The transfer function for an ideal proportional plus reset controller (reset time T) is_______________? |
| A. | Kc[1 + (1/TS)] |
| B. | Kc(1 + TS) |
| C. | Kc/(1 + TS) |
| D. | Kc/[1 + (s/T)] |
| Answer» B. Kc(1 + TS) | |
| 55. |
The transfer function for a PID controller is (where, η i is the integral (reset) time and ηD is the derivative time.) ? |
| A. | Kc(1 + ηis + ηD ). s |
| B. | Kc[1 + (1/ηis) + ηD . s) |
| C. | Kc(1 + ηis + (1/ηD . s) |
| D. | None of these |
| Answer» C. Kc(1 + ηis + (1/ηD . s) | |
| 56. |
The transfer function for a P-D controller is________________? |
| A. | Kc(1+ηD s) |
| B. | Kc(1 +1/ηD s) |
| C. | Kc ηD s |
| D. | Kc/ηD s |
| Answer» B. Kc(1 +1/ηD s) | |
| 57. |
The time taken for a radioactive element to reduce to 50% of its original weight is _____________ years, if its half life period is 12 years? |
| A. | 24 |
| B. | 18 |
| C. | 6 |
| D. | 36 |
| Answer» C. 6 | |
| 58. |
The time constant of a unity gain, first order plus time delay process is 5 min. If the phase lag at a frequency of 0.2 rad/min is 60°, then the dead time (in minutes) is________________? |
| A. | 5π/12 |
| B. | π/6 |
| C. | π/12 |
| D. | π/3 |
| Answer» B. π/6 | |
| 59. |
The time constant of a first order process with resistance R and capacitance C is__________________? |
| A. | R + C |
| B. | R – C |
| C. | RC |
| D. | 1/RC |
| Answer» D. 1/RC | |
| 60. |
The thermal emf-temperature relationship of most thermocouples is_________________? |
| A. | Linear |
| B. | Parabolic |
| C. | Exponential |
| D. | Square root |
| Answer» C. Exponential | |
| 61. |
The term analogous to voltage in a single tank system is the_______________? |
| A. | Heat content of the system |
| B. | Liquid volume in the tank |
| C. | Flow rate |
| D. | Level of liquid |
| Answer» E. | |
| 62. |
The term analogous to the electrical current in a thermal system is the_________________? |
| A. | Temperature difference |
| B. | Heat flow rate |
| C. | Heat content in the system |
| D. | None of these |
| Answer» C. Heat content in the system | |
| 63. |
The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an _____________ thermocouple? |
| A. | Chromel-alumel |
| B. | Iron-constantan |
| C. | Platinum-platinum/rhodium |
| D. | None of these |
| Answer» C. Platinum-platinum/rhodium | |
| 64. |
The second order system with the transfer function 4/(s2 + 2s + 4) has a damping ratio of ___________________? |
| A. | 2.0 |
| B. | 0.5 |
| C. | 1.0 |
| D. | 4.0 |
| Answer» C. 1.0 | |
| 65. |
The root locus plot of the roots of the characteristics equation of a closed loop system having the open loop transfer function K (s + 1)/[2 (2s + 1) (3s + 1)] will have a definite number of loci for variation of K from 0 to ∞. The number of loci is_______________? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 66. |
The root locus method, a pole of a transfer function G(s) is the value of s for which G(s) approaches ___________________? |
| A. | -1 |
| B. | 0 |
| C. | 1 |
| D. | ∞ |
| Answer» E. | |
| 67. |
The response of two tanks of same size and resistance in series is __________________? |
| A. | Under damped |
| B. | Critically damped |
| C. | Over damped |
| D. | None of the above |
| Answer» C. Over damped | |
| 68. |
The pressure sensing element of elastic type pressure gauge is never made in the form of a_________________? |
| A. | Bellow |
| B. | Diaphragm |
| C. | Strip |
| D. | Bourdon tube |
| Answer» D. Bourdon tube | |
| 69. |
The operation of a Rotameter is based on ________________? |
| A. | Variable flow area |
| B. | Rotation of a turbine |
| C. | Pressure drop across a nozzle |
| D. | Pressure at a stagnation point |
| Answer» B. Rotation of a turbine | |
| 70. |
The open loop transfer function of a process is K [{(s + 1) (s + 4)}/{(s + 2) (s + 3)}]. In the root locus diagram, the poles will be at ___________________? |
| A. | -1, -4 |
| B. | 1, 4 |
| C. | -2, -3 |
| D. | 2, 3 |
| Answer» D. 2, 3 | |
| 71. |
The open loop transfer function of a control system is KR/(1 + TS). This represents ______________? |
| A. | A first order system |
| B. | Dead time system |
| C. | A first order time lag |
| D. | A second order system |
| Answer» B. Dead time system | |
| 72. |
The offset introduced by proportional controller with gain Kc in response of first order system can be reduced by ____________________? |
| A. | Reducing value of Kc |
| B. | Introducing integral control |
| C. | Introducing derivative control |
| D. | None of the above |
| Answer» C. Introducing derivative control | |
| 73. |
The ____________ of the fluid contained in the temperature sensing element (i.e., bulb) of filled system thermometers changes with change in temperature ? |
| A. | Pressure |
| B. | Volume |
| C. | Viscosity |
| D. | All A., B. and C. |
| Answer» E. | |
| 74. |
The ____________ of a vapor pressure thermometer is a secondary element ? |
| A. | Pointer |
| B. | Bourdon tube |
| C. | Bulb |
| D. | None of these |
| Answer» C. Bulb | |
| 75. |
The ______________ of a vapor pressure thermometer is a primary element? |
| A. | Pointer |
| B. | Bourdon tube |
| C. | Bulb |
| D. | None of these |
| Answer» D. None of these | |
| 76. |
The _____________ of a vapor pressure thermometer is a functioning element? |
| A. | Pointer |
| B. | Bourdon tube |
| C. | Bulb |
| D. | None of these |
| Answer» B. Bourdon tube | |
| 77. |
The maximum service temperature for fibre glass used as thermocouple wire insulation material is __________ °C? |
| A. | 250 |
| B. | 500 |
| C. | 750 |
| D. | 1000 |
| Answer» C. 750 | |
| 78. |
The level of a liquid under pressure can be determined using___________________? |
| A. | Bubbler system |
| B. | Differential pressure manometer |
| C. | Diaphragm box system |
| D. | Air-trap system |
| Answer» C. Diaphragm box system | |
| 79. |
The Laplace transform of exp(at), where a > 0, is defined only for the Laplace parameter, s > a since______________? |
| A. | The function is exponential |
| B. | The Laplace transform of integral of exp(at) has finite values only for s > a |
| C. | The Laplace transform integral of exp(at) has initial values only for s > a |
| D. | The function exp(at) is piece-wise continuous only for s > a |
| Answer» C. The Laplace transform integral of exp(at) has initial values only for s > a | |
| 80. |
The inverse Laplace transform of the function f(S) = 1/S (1 + S) is_________________? |
| A. | 1 + et |
| B. | 1 – et |
| C. | 1 + e-t |
| D. | 1 – e-t |
| Answer» E. | |
| 81. |
The initial value (t = 0) of the unit step response of the transfer function [(s + 1)/(2s + 1)] is__________________? |
| A. | 0 |
| B. | ½ |
| C. | 1 |
| D. | 2 |
| Answer» C. 1 | |
| 82. |
The function of a transducer is to _______________ ? |
| A. | Modify the input signal |
| B. | Amplify the input signal |
| C. | Convert the primary signal into a more useful quantity, usually an electric impulse |
| D. | Codify/decodify the input signal |
| Answer» D. Codify/decodify the input signal | |
| 83. |
The frequency response of a first order system, has a phase shift with lower and upper bounds given by________________? |
| A. | – ∞, π/2 |
| B. | -π/2, π/2 |
| C. | -π/2, 0 |
| D. | 0, π/2 |
| Answer» E. | |
| 84. |
The frequency response of a dynamic element shows a constant magnitude ratio at all frequencies. The element exhibits a negative phase shift at all frequencies. The absolute value of the phase shift increases linearly with frequency. The element has the transfer function ? |
| A. | e-ηS |
| B. | (T1S + 1)/(T2S + 1) |
| C. | (T1S/(T2S + 1) |
| D. | (T1S + 1)/(T2S |
| Answer» B. (T1S + 1)/(T2S + 1) | |
| 85. |
The frequency at which maximum amplitude ratio is attained is called the ______________ frequency? |
| A. | Corner |
| B. | Resonant |
| C. | Cross-over |
| D. | Natural |
| Answer» C. Cross-over | |
| 86. |
The experimental response of the controlled variable y(t) for a step change of magnitude ‘P’ in the manipulated variable x(t) is shown below: The appropriate transfer function of the process is_________________? |
| A. | (Q/P) e-(Q/R)S/(TdS + 1) |
| B. | (Q/R) e-TdS/(Q/P) (S + 1) |
| C. | (Q/P) e-TdS/(Q/R) (S + 1) |
| D. | (Q/R) e-(P/Q)S/(TdS + 1) |
| Answer» D. (Q/R) e-(P/Q)S/(TdS + 1) | |
| 87. |
The deflection of the free end of the bimetallic strips in a bimetallic thermometer with temperature is nearly__________________? |
| A. | Linear |
| B. | Non-linear |
| C. | Parabolic |
| D. | Hyperbolic |
| Answer» B. Non-linear | |
| 88. |
The deflection in diaphragm (which is used as pressure sensor in pneumatic and electronic instruments) is dependent on the metal thickness, its diameter D. and shape & number of corrugations. Its deflection is proportional to_______________? |
| A. | d |
| B. | d2 |
| C. | d3 |
| D. | d4 |
| Answer» E. | |
| 89. |
The closed loop pole of a stable second order system could be_______________? |
| A. | Both real and positive |
| B. | Complex conjugate with positive real parts |
| C. | Both real and negative |
| D. | One real positive and the other real negative |
| Answer» B. Complex conjugate with positive real parts | |
| 90. |
The characteristic equation for the control system with a closed loop transfer function G1/1 + G2 is given by 1 + G2 = 0. The characteristic equation for the control system_________________? |
| A. | Depends only upon the open loop transfer function |
| B. | Determines its stability |
| C. | Is the same for set point or load changes |
| D. | All A , B & C. |
| Answer» E. | |
| 91. |
The calibration data of a thermocouple with its cold junction at 0°C are given below. The hot junction of the thermocouple is placed in a bath at 80°C, while its cold junction is at 20°C. What is the emf of thermocouple ? |
| A. | 3.26 mv |
| B. | 0.80 mv |
| C. | 2.46 mv |
| D. | 2.43 mv |
| Answer» D. 2.43 mv | |
| 92. |
The amplitude ratio for the sinusoidal response of __________ is < 1? |
| A. | Transportation lag |
| B. | First order system |
| C. | Second order system |
| D. | None of these |
| Answer» C. Second order system | |
| 93. |
The amplitude ratio for the sinusoidal response of a _____________ is 1? |
| A. | First order system |
| B. | Second order system |
| C. | Transportation lag |
| D. | None of these |
| Answer» D. None of these | |
| 94. |
Routh test_________________? |
| A. | Criterion provides information about the actual location of roots |
| B. | Cannot be used to test the stability of a control system containing transportation lag |
| C. | Criterion is not applicable to systems with polynomial characteristic equation |
| D. | Cannot determine as to how many roots of the characteristics equation have positive real roots |
| Answer» C. Criterion is not applicable to systems with polynomial characteristic equation | |
| 95. |
Routh stability method uses ______________ loop transfer function? |
| A. | Open |
| B. | Closed |
| C. | Either A. or B. |
| D. | Neither A. nor B. |
| Answer» C. Either A. or B. | |
| 96. |
Response of a system to a sinusoidal input is called _____________ response? |
| A. | Impulse |
| B. | Unit step |
| C. | Frequency |
| D. | None of these |
| Answer» D. None of these | |
| 97. |
Response of a linear control system for a change in set point is called __________________? |
| A. | Frequency response |
| B. | Transient response |
| C. | Servo problem |
| D. | Regulator problem |
| Answer» D. Regulator problem | |
| 98. |
Resistance of a gas in a vessel is given by (where, P = pressure, V = volume of the vessel, n = no. of moles of the gas, R = gas constant) ? |
| A. | V/nRT |
| B. | nRT/V |
| C. | nRT/P |
| D. | P/nRT |
| Answer» B. nRT/V | |
| 99. |
Reset rate is the another term used for ____________ time? |
| A. | Dead |
| B. | Integral |
| C. | Derivative |
| D. | None of these |
| Answer» C. Derivative | |
| 100. |
Relationship between absorption/evolution of heat at the thermocouple junctions and the current flow in the circuit is given by _____________ effect? |
| A. | Peltier |
| B. | Thomson |
| C. | Seebeck |
| D. | None of these |
| Answer» B. Thomson | |