MCQOPTIONS
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MCQOPTIONS
This section includes 830 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
A control system has the following transfer function. The initial value of the corresponding time function is |
| A. | 1 |
| B. | 1/8 |
| C. | 7/8 |
| D. | -1 |
| Answer» B. 1/8 | |
| 102. |
The root locus plot of the roots of the characteristics equation of a closed loop system having the open loop transfer function given below, will have a definite number of loci for variation of K from 0 to ∞. The number of loci is |
| A. | 1 |
| B. | 3 |
| C. | 4 |
| D. | 2 |
| Answer» C. 4 | |
| 103. |
__________ is undesirable in thermocouples used in industries. |
| A. | Linear relation of emf to temperature |
| B. | Corrosion resistance |
| C. | Oxidation resistance |
| D. | Non-linear relation of emf to temperature |
| Answer» E. | |
| 104. |
For the time domain function f(t) = t, the Laplace transform of following equation is given by |
| A. | 1/2 S³ |
| B. | 2/S³ |
| C. | 1/S³ |
| D. | 2/S² |
| Answer» D. 2/S² | |
| 105. |
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. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 106. |
For the block diagram shown below, the characteristic equation is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 107. |
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 | |
| 108. |
Which of the systems having the following transfer function is stable ? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 109. |
A process is initially at steady state with its output y=1 for an input u=1. The input is suddenly changed to 2 at time t=0. The output response is y(t)=1+2t. The transfer function of the process is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 110. |
Transfer functions X/Y for which of the following block diagrams is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 111. |
The transfer function for a first order process with time delay is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 112. |
The unit step response of the following transfer function reaches its final steady state assymptotically after |
| A. | a monotonic increase. |
| B. | a monotonic decrease. |
| C. | initially increasing and then decreasing. |
| D. | increasing decreasing and then increasing. |
| Answer» B. a monotonic decrease. | |
| 113. |
An ideal PID controller has the transfer function [1 + 1/0.55 + 0.25 ]. The frequency at which the magnitude ratio of the controller is 1, is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 114. |
What is the overall transfer function (C/R) of the following block diagram if G = G₁. G₂. G₃ and H = H₁.H₂. |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 115. |
The transfer function of a second order system is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 116. |
The Laplace transform of a sinusoidal function (eg; sin at) is represented by the curve |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 117. |
Water is entering a storage tank at a temperature T₀ and flow rate Q₀ and leaving at a flow rate Q and temperature T. There are negligible heat losses in the tank. The area of cross-section of the tank is A₀. The model that describes the dynamic variation of temperature of water in the tank with time is given as : |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 118. |
The open loop transfer function of a process is given below. 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 | |
| 119. |
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. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 120. |
Block diagram of a simple standard control system is shown below in the figure. Which of the following statement about the above control system is wrong ? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 121. |
The transfer function of a pure dead time system with dead time τd is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 122. |
Pick out the symbol for "locally mounted instrument" in instrumentation diagram. |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 123. |
Which of following error integral is considered as the best criterion in controller settings ? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 124. |
The transfer function for a PID controller is (where, τᵢ is the integral (reset) time and τD is the derivative time.) |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 125. |
For an input forcing function, X(t) = 2t², the Laplace transform of this function is |
| A. | 2/s² |
| B. | 4/s² |
| C. | 2/s³ |
| D. | 4/s³ |
| Answer» E. | |
| 126. |
Which of the following controllers has the least maximum deviation? |
| A. | P-controller |
| B. | P-I controller |
| C. | P-I-D controller |
| D. | P-D controller |
| Answer» E. | |
| 127. |
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 | |
| 128. |
Helium gas constant volume thermometer is suitable for the measurement of a temperature of __________ °C. |
| A. | < 100 |
| B. | < 0 |
| C. | > 0 |
| D. | > 800 |
| Answer» C. > 0 | |
| 129. |
Nitrogen gas constant volume thermometer is suitable for measuring a temperature of __________ °C. |
| A. | 0-100 |
| B. | < 0 |
| C. | > 100 |
| D. | > 50 |
| Answer» D. > 50 | |
| 130. |
Silver point temperature is __________ °C. |
| A. | 760.5 |
| B. | 860.5 |
| C. | 960.5 |
| D. | 1060.5 |
| Answer» D. 1060.5 | |
| 131. |
Which of the following instruments is not used for measuring sub-zero ( |
| A. | Platinum resistance thermometer |
| B. | Mercury in glass thermometer |
| C. | Vapor pressure thermometer |
| D. | Radiation pyrometer |
| Answer» E. | |
| 132. |
Which of the following is never used as an element of industrial resistance thermometer? |
| A. | Lead |
| B. | Nickel |
| C. | Copper |
| D. | 30% iron + 70% nickel |
| Answer» B. Nickel | |
| 133. |
Thermistors are made of |
| A. | Ultra pure metals |
| B. | Metal oxides |
| C. | Iron-copper alloys |
| D. | Nickel-chromium alloys |
| Answer» C. Iron-copper alloys | |
| 134. |
Liquid column manometers are used for measuring the pressure __________ kgf/cm² . |
| A. | > 2(gage) |
| B. | < 3 (gage) |
| C. | < 10 (gage) |
| D. | < atmospheric |
| Answer» C. < 10 (gage) | |
| 135. |
The transfer function of a process is 1/(16s² + 8s + 4). If a step change is introduced into the system, then the response will be |
| A. | Under damped |
| B. | Critically damped |
| C. | Over damped |
| D. | None of these |
| Answer» B. Critically damped | |
| 136. |
Platinum resistance thermometer can be used upto antimony point which is __________ °C, and is the temperature of equilibrium between solid antimony & liquid antimony at normal atmospheric pressure. |
| A. | 961.93 |
| B. | 630.74 |
| C. | 1064.43 |
| D. | 1261.93 |
| Answer» C. 1064.43 | |
| 137. |
For measuring the temperature of a red hot furnace, which is the most suitable instrument? |
| A. | Platinum resistance thermometer |
| B. | Thermocouple |
| C. | Optical pyrometer |
| D. | Bimetallic thermometer |
| Answer» D. Bimetallic thermometer | |
| 138. |
Which thermocouple can be used to measure a temperature of around 1400°C ? |
| A. | Copper-constantan |
| B. | Aluminium-chromel |
| C. | Platinum-platinum+rhodium |
| D. | None of these |
| Answer» D. None of these | |
| 139. |
Which of the following is not a variable area flow meter? |
| A. | Piston type meter |
| B. | Rotameter |
| C. | Magnetic flow meter |
| D. | Orifice and tapered plug meter |
| Answer» D. Orifice and tapered plug meter | |
| 140. |
Which of the following thermocouples is capable of measuring a temperature of -50°C? |
| A. | Platinum - platinum + rhodium |
| B. | Chromel - alumel |
| C. | Iron-constantan |
| D. | Copper - constantan |
| Answer» B. Chromel - alumel | |
| 141. |
Which of the following thermocouples can measure the maximum temperature? |
| A. | Platinum-rhodium |
| B. | Tungsten-molybdenum |
| C. | Chromel-alumel |
| D. | Iron-constantan |
| Answer» C. Chromel-alumel | |
| 142. |
Which of the following can not measure a temperature of 1600°C ? |
| A. | Platinum resistance thermometer |
| B. | Thermocouple |
| C. | Photo-electric pyrometer |
| D. | Radiation pyrometer |
| Answer» B. Thermocouple | |
| 143. |
__________ thermometer can not measure sub-zero (< 0° C) temperature, |
| A. | Mercury in glass |
| B. | Bimetallic |
| C. | Vapor pressure |
| D. | Resistance |
| Answer» C. Vapor pressure | |
| 144. |
Temperature of molten pig iron (1450°C) and molten slag (1500°C) flowing out of a blast furnace is measured by a/an |
| A. | Chromel-alumel thermocouple |
| B. | Optical pyrometer |
| C. | Radiation pyrometer |
| D. | Either B or C |
| Answer» E. | |
| 145. |
Mercury thermometer is commonly used for low temperature measruement. The freezing point and boiling point of mercury are respectively __________ °C. |
| A. | - 39 and 350 |
| B. | - 51 and 439 |
| C. | - 79 and 395 |
| D. | - 10 and 425 |
| Answer» B. - 51 and 439 | |
| 146. |
Which of the following thermocouples is incapable of measuring sub-zero (i.e., < 0°C) temperature? |
| A. | Chromel-alumel |
| B. | Iron-constantan |
| C. | Platinum-platinum + rhodium |
| D. | Copper-constantan |
| Answer» D. Copper-constantan | |
| 147. |
A constant volume gas thermometer employing __________ is used to measure sub-zero (i.e., < 0° C) temperature. |
| A. | Helium |
| B. | Hydrogen |
| C. | Nitrogen |
| D. | None of these |
| Answer» B. Hydrogen | |
| 148. |
A mercury thermometer can not be used to measure the temperature below the freezing point of mercury, which is __________ °C. |
| A. | -38.9 |
| B. | -11.9 |
| C. | -60.9 |
| D. | -80.9 |
| Answer» B. -11.9 | |
| 149. |
Photoelectric pyrometers are suitable in the temperature range of __________ °C. |
| A. | 400-1600 |
| B. | 800-1600 |
| C. | 800-2500 |
| D. | 400-1000 |
| Answer» C. 800-2500 | |
| 150. |
Which of the following is an undesirable dynamic characteristic of an instrument? |
| A. | Reproducibility |
| B. | Dead zone |
| C. | Time lag |
| D. | Static error |
| Answer» D. Static error | |