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.
| 551. |
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 | |
| 552. |
Ordinary mercury in glass thermometer is used for measuring temperature upto 120°C. However, for measuring higher temperature upto __________ °C, thermometer is made by filling nitrogen under pressure above the mercury, which stops the evaporation of mercury and reduces the chance of broken thread of mercury.$ |
| A. | 250 |
| B. | 350 |
| C. | 550 |
| D. | 700 |
| Answer» D. 700 | |
| 553. |
E.m.f. generated by thermocouples is of the order of |
| A. | millivolts |
| B. | microvolts |
| C. | volts |
| D. | kilo volts |
| Answer» B. microvolts | |
| 554. |
Alphatron measures pressure __________ microns. |
| A. | < 1 |
| B. | < 3 |
| C. | > 3 |
| D. | < 0.1 |
| Answer» D. < 0.1 | |
| 555. |
Which of the following is not a differential pressure flow meter ? |
| A. | Rotameter |
| B. | Flow nozzle |
| C. | Orificemeter |
| D. | Venturimeter |
| Answer» B. Flow nozzle | |
| 556. |
Phase lag of the frequency response of a second order system to a sinusoidal forcing function |
| A. | is 30° |
| B. | is 90° at the most |
| C. | approaches 180° asymptotically |
| D. | is 120° |
| Answer» D. is 120¬∞ | |
| 557. |
Emf developed by a thermocouple while measuring a temperature of 800°C is about 31 mV. The type of thermocouple used is$ |
| A. | chromel-alumel |
| B. | iron-constantan |
| C. | platinum-platinum+rhodium |
| D. | none of these. |
| Answer» B. iron-constantan | |
| 558. |
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. | Q0(T0 - T) = Ac . |
| B. | Q0T0 - QT = Ac . |
| C. | Q(T0 - T) = Ac . |
| D. | Q(T0 - T) = Ac . |
| Answer» B. Q0T0 - QT = Ac . | |
| 559. |
Stroboscope is used for the measurement of |
| A. | rpm of a flywheel |
| B. | frequency of light |
| C. | depression of freezing point |
| D. | liquid level under pressure |
| Answer» B. frequency of light | |
| 560. |
Accurate temperature measurement performance of a radiation pyrometer can not be affected, if the |
| A. | enhancement or attentuation of redia-tion occurs in the sighting path. |
| B. | object and surrounding are at almost the same temperature. |
| C. | object has varying emissivity. |
| D. | object is transparent. |
| Answer» C. object has varying emissivity. | |
| 561. |
The offset introduced by proportional controller with gain Kcin 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. | |
| 562. |
The unit step response of the transfer functionreaches 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. | |
| 563. |
Zirconia probe is used for the measurement of |
| A. | humidity of air. |
| B. | % CO2 in flue gas. |
| C. | % O2 in flue gas. |
| D. | speed of a submarine. |
| Answer» D. speed of a submarine. | |
| 564. |
Which is the strongest paramagnetic gas? |
| A. | CO2 |
| B. | O2 |
| C. | NO |
| D. | NO2 |
| Answer» C. NO | |
| 565. |
__________ is an example of distributed parameter system |
| A. | Tubular reactor |
| B. | CSTR |
| C. | On-off controller |
| D. | none of these |
| Answer» B. CSTR | |
| 566. |
The root locus plot of the roots of the characteristics equation of a closed loop system having the open loop transfer function will have a definite num-ber of loci for variation of K from 0 to ‚àû. The number of loci is$ |
| A. | 1 |
| B. | 3 |
| C. | 4 |
| D. | 2 |
| Answer» C. 4 | |
| 567. |
__________ are analysed using a polarograph. |
| A. | Isotonic solutions |
| B. | Solids |
| C. | Liquids |
| D. | Gases |
| Answer» C. Liquids | |
| 568. |
Very low pressure is expressed in microns(μ), which is equal to __________ mm of Hg coloumn (absolute) at 0°C.$ |
| A. | 0.0001 |
| B. | 0.001 |
| C. | 0.01 |
| D. | 0.1 |
| Answer» C. 0.01 | |
| 569. |
Emf generated in a thermocouple depends on the temperature |
| A. | of cold junction only. |
| B. | of hot junction only. |
| C. | difference between hot and cold junctions. |
| D. | difference between cold junction and atmospheric temperature. |
| Answer» D. difference between cold junction and atmospheric temperature. | |
| 570. |
A system with transfer function is of __________ order. |
| A. | zero |
| B. | 1st |
| C. | 2nd |
| D. | 3rd |
| Answer» C. 2nd | |
| 571. |
The thermal emf-temperature relationship of most thermocouples is |
| A. | linear |
| B. | parabolic |
| C. | exponential |
| D. | square root |
| Answer» C. exponential | |
| 572. |
The initial value (t=0) of the unit step response of the transfer function [(s + 1)/(2s + 1)] is |
| A. | 0 |
| B. | 43497 |
| C. | 1 |
| D. | 2 |
| Answer» C. 1 | |
| 573. |
Psychrometer determines the |
| A. | humidity of gases |
| B. | moisture content of solids |
| C. | water of crystallisation |
| D. | hygroscopic nature of solids |
| Answer» B. moisture content of solids | |
| 574. |
Specific gravity of a liquid can not be measured by a/an |
| A. | anemometer |
| B. | specific gravity bottle |
| C. | pycnometer |
| D. | hydrometer |
| Answer» B. specific gravity bottle | |
| 575. |
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 | |
| 576. |
In a closed loop system, the process to be controlled is an integrating process with transfer function l/2s. The controller proposed to be used in an integral controller with transfer function 1/T1s. When a step change in set point is applied to such a closed loop system, the controlled variable will exhibit |
| A. | overdamped response. |
| B. | underdamped response. |
| C. | undamped response. |
| D. | unstable response. |
| Answer» C. undamped response. | |
| 577. |
Pressure of 0.01 psi (absolute) can be measured by __________ gauge. |
| A. | ionisation |
| B. | Pirani |
| C. | Mcloid |
| D. | none of these |
| Answer» D. none of these | |
| 578. |
Which of the following thermocouples is the most suitable for measuring a temperature of about 1600°C in an oxidizing atmosphere ?$ |
| A. | Platinum-platinum + rhodium |
| B. | Iron-constantan |
| C. | Copper-constantan |
| D. | Chromel-alumel |
| Answer» B. Iron-constantan | |
| 579. |
The fluid used in hydraulic controller is |
| A. | water |
| B. | steam |
| C. | air |
| D. | oil |
| Answer» E. | |
| 580. |
A pyrheliometer is an instrument used for measuring the |
| A. | bright sunshine period. |
| B. | beam radiation. |
| C. | diffuse radiation. |
| D. | none of these. |
| Answer» C. diffuse radiation. | |
| 581. |
Thermal conductivity based continuous flue gas analyser makes use of varying thermal conductivity of the constituents of flue gases. Which of the following constituents of flue gases has the maximum thermal conductivity ? |
| A. | CO2 |
| B. | N2 |
| C. | O2 |
| D. | CO |
| Answer» B. N2 | |
| 582. |
Bourdon tube is never made of |
| A. | phosphor bronze |
| B. | monel metal |
| C. | stainless steel |
| D. | cast iron |
| Answer» E. | |
| 583. |
__________ type of element is normally not used in the bimetallic thermometers. |
| A. | Flat spiral |
| B. | Bourdon tube |
| C. | Single helix |
| D. | Multiple helix |
| Answer» C. Single helix | |
| 584. |
Out of the following temperature measuring instruments, the measurement accuracy will be minimum for the |
| A. | mercury in glass thermometer. |
| B. | optical pyrometer. |
| C. | iron-constantan thermocouple. |
| D. | alcohol filled thermometer. |
| Answer» C. iron-constantan thermocouple. | |
| 585. |
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 | |
| 586. |
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. | |
| 587. |
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 | |
| 588. |
Stabilising time for the controllers is the time required for the response to reach __________ percent of its ultimate value. |
| A. | 63.2 |
| B. | 87.5 |
| C. | 95 |
| D. | 100 |
| Answer» D. 100 | |
| 589. |
Phase lag of the sinusoidal response of a first order system is |
| A. | 120° |
| B. | 30° |
| C. | 180° |
| D. | 90° |
| Answer» E. | |
| 590. |
Working principle of mercury in glass thermometer is based on volumetric expansion of mercury with increase in temperature. Which of the following undergoes minimum volumetric expansion for a given temperature change ? |
| A. | Water |
| B. | Mercury |
| C. | Methyl alcohal |
| D. | Carbon-tetrachloride |
| Answer» C. Methyl alcohal | |
| 591. |
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 | |
| 592. |
Which of the following is not a speed measuring instrument ? |
| A. | Psychrometer |
| B. | Stroboscope |
| C. | Tachometer |
| D. | All (a), (b) and (c) |
| Answer» B. Stroboscope | |
| 593. |
Thermodynamic celcius scale of temperature measurement is |
| A. | defined on the basis of melting point of ice and evaporation temperature of water vapor. |
| B. | defined on the basis of melting point of ice and condensation temperature of water vapor. |
| C. | having an interval of 100° between ice point to steam point. |
| D. | both (b) and (c) |
| Answer» E. | |
| 594. |
Small furnace draught is accurately measured by an inclined tube manometer, in which the manometric liquid used most commonly is |
| A. | water |
| B. | carbon tetrachloride |
| C. | paraffin |
| D. | ethylene glycol |
| Answer» D. ethylene glycol | |
| 595. |
"A control system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at the crossover frequency." This is __________ criterion. |
| A. | Bode stability |
| B. | Nyquist |
| C. | Routh stability |
| D. | none of these |
| Answer» B. Nyquist | |
| 596. |
Which is the most suitable instrument for measuring pressure below 3 microns ? |
| A. | Mcleoid gauge |
| B. | Alphatron |
| C. | Ionisation gauge |
| D. | Bourdon guage |
| Answer» D. Bourdon guage | |
| 597. |
When the damping co-efficient (ξ) is unity, the system is$ |
| A. | Overdamped. |
| B. | Critically damped. |
| C. | Underdamped. |
| D. | Highly fluctuating. |
| Answer» C. Underdamped. | |
| 598. |
Temperature control of an exothermic chemical reaction taking place in a CSTR is done with the help of cooling water flowing in a jacket around the reactor. The types of valve and controller action to be recommended are |
| A. | air to open valve with the controller direct acting. |
| B. | air to close valve with the controller indirect acting. |
| C. | air to open valve with the controller indirect acting. |
| D. | air to close valve with the controller direct acting. |
| Answer» D. air to close valve with the controller direct acting. | |
| 599. |
Flow rate measurement of hostile acids and alkalis can be most suitably done by a/an |
| A. | venturimeter |
| B. | orificemeter |
| C. | magnetic flow meter |
| D. | hot wire anemometer |
| Answer» D. hot wire anemometer | |
| 600. |
A first order system with unity gain and time constant τ is subjected to a sinusoidal input of frequency w = 1/τ. The amplitude ratio for this system is$ |
| A. | 1 |
| B. | 0.5 |
| C. | 43497 |
| D. | 0.25 |
| Answer» D. 0.25 | |