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.
| 501. |
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 | |
| 502. |
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 | |
| 503. |
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. | |
| 504. |
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 ‚à û. The number of loci is# |
| A. | 1 |
| B. | 3 |
| C. | 4 |
| D. | 2 |
| Answer» C. 4 | |
| 505. |
Temperature measurement by optical pyrometer is done above __________ point, which is 1063°C.# |
| A. | Antimony |
| B. | Gold |
| C. | Silver |
| D. | Nickel |
| Answer» C. Silver | |
| 506. |
__________ is the static characteristics of an instrument, |
| A. | Response |
| B. | Tine lag |
| C. | Drift |
| D. | dynamic error |
| Answer» D. dynamic error | |
| 507. |
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 | |
| 508. |
Dead zone is the |
| A. | same as time constant. |
| B. | same as transportation lag. |
| C. | maximum change in the variable that does not change the reading of the instrument. |
| D. | none of these. |
| Answer» D. none of these. | |
| 509. |
Minute depression of freezing point of a liquid solvent on addition of a solid solute can be best measured by a |
| A. | Beckman thermometer |
| B. | dilatometer |
| C. | mercury thermometer |
| D. | bimetallic thermometer |
| Answer» B. dilatometer | |
| 510. |
Suppose that the gain, time constant and dead time of a process with the following transfer function:Gc(s) = 10 exp( - 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain Kc of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as$ |
| A. | 8, 0.6, 0.08 |
| B. | 12, 0.6, 0.12 |
| C. | 8, 0.6, 0.12 |
| D. | 12, 0.4, 0.08 |
| Answer» C. 8, 0.6, 0.12 | |
| 511. |
Bode diagram are generated from output response of the system subjected to which of the following input? |
| A. | Impulse |
| B. | Step |
| C. | Ramp |
| D. | Sinusoidal |
| Answer» E. | |
| 512. |
The unit step response of the transfer function 1/(s2 + 2s + 3) |
| A. | has a non-zero slope at the origin. |
| B. | has a damped oscillatory characteristics. |
| C. | is overdamped |
| D. | is unstable |
| Answer» C. is overdamped | |
| 513. |
Maximum differential pressure in liquid manometer is __________ psi. |
| A. | 20 |
| B. | 30 |
| C. | 40 |
| D. | 50 |
| Answer» C. 40 | |
| 514. |
Positioning controllers are used for |
| A. | low loads |
| B. | temperature changes |
| C. | high loads |
| D. | flow rate changes |
| Answer» D. flow rate changes | |
| 515. |
A first order system with a time constant of 1 min is subjected to frequency response analysis. At an input frequency of 1 radian/min, the phase shift is |
| A. | 45° |
| B. | -90° |
| C. | -180° |
| D. | -45° |
| Answer» E. | |
| 516. |
Operating range of a temperature measuring instrument is 800 to 1600°C. It could be a/an __________ pyrometer.$ |
| A. | radiation |
| B. | optical |
| C. | photoelectric |
| D. | none of these |
| Answer» D. none of these | |
| 517. |
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 | |
| 518. |
Cascade control means |
| A. | feed forward control. |
| B. | more than one feed-back loop. |
| C. | on-off control. |
| D. | one feed-back loop. |
| Answer» C. on-off control. | |
| 519. |
Thermal well made of __________ gives the fastest speed of response, while measuring temperature by thermocouples. |
| A. | steel |
| B. | vycor (a glass) |
| C. | nichrome |
| D. | inconel |
| Answer» C. nichrome | |
| 520. |
The transfer function of a process is . 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 | |
| 521. |
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 | |
| 522. |
Temperature of __________ can not be measured by an optical or radiation pyrometer. |
| A. | hot blast (air) from stoves |
| B. | molten slag flowing out of blast furnace |
| C. | combustion space in boilers |
| D. | rotary limestone calcination kiln |
| Answer» B. molten slag flowing out of blast furnace | |
| 523. |
Polarograph is meant for the analysis of |
| A. | gaseous mixture |
| B. | miscible liquids |
| C. | solids |
| D. | isotopes |
| Answer» D. isotopes | |
| 524. |
The transfer function of a pure dead time system with dead time τd is$ |
| A. | 1/(τds + 1) |
| B. | τds + 1 |
| C. | e-τss |
| D. | eτds |
| Answer» D. eœÑds | |
| 525. |
Continuous measurement of moisture content of paper in paper industry is done by measuring the |
| A. | thermal conductivity through the paper |
| B. | electrical resistance through the paper |
| C. | magnetic susceptibility |
| D. | none of these |
| Answer» C. magnetic susceptibility | |
| 526. |
Liquid discharge from a tank or reservoir can not be measured by |
| A. | orificemeters |
| B. | weirs |
| C. | mouthpieces |
| D. | notches |
| Answer» B. weirs | |
| 527. |
Which of the following thermocouples has the least temperature measurement range? |
| A. | Copper-constantan |
| B. | Chromel-alumel |
| C. | Platinum-platinum/rhodium |
| D. | Iron-constantan |
| Answer» B. Chromel-alumel | |
| 528. |
A non-linear system will have __________ steady state values. |
| A. | one |
| B. | more than one |
| C. | two |
| D. | three |
| Answer» C. two | |
| 529. |
Bode diagram is a plot of |
| A. | log (AR) vs. log (f) and (Φ) vs. log (f). |
| B. | log (AR) vs. f and log Φ vs.f. |
| C. | AR vs. log (f) and Φ vs. log (f). |
| D. | none of these. |
| Answer» B. log (AR) vs. f and log Œ¶ vs.f. | |
| 530. |
Compositional analysis of flue gas coming out of a furnace in respect of O2 and CO2% can be continuously done by a/an |
| A. | orsat apparatus |
| B. | thermal conductivity cell |
| C. | zirconia probe |
| D. | chromatograph |
| Answer» C. zirconia probe | |
| 531. |
A manometer measures the __________ pressure. |
| A. | atmospheric |
| B. | absolute |
| C. | gauge |
| D. | none of these |
| Answer» D. none of these | |
| 532. |
Radiation thermometer can not measure the temperature |
| A. | inside a pressure vessel. |
| B. | of an object without coming in contact with it. |
| C. | of liquid oxygen. |
| D. | of moving objects at high temperature. |
| Answer» D. of moving objects at high temperature. | |
| 533. |
Presence of a small amount of water in the organic systems can be determined by the __________ method. |
| A. | electrical conductivity |
| B. | polarimetry |
| C. | emission spectroscopy |
| D. | dielectric constant end loss factor |
| Answer» E. | |
| 534. |
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 | |
| 535. |
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 | |
| 536. |
Dilatometer is used to measure |
| A. | stress |
| B. | strain |
| C. | deflection |
| D. | contraction/expansion due to changes in temperature |
| Answer» E. | |
| 537. |
Working principle of mercury in glass thermometer is |
| A. | volumetric expansion. |
| B. | pressure rise with temperature. |
| C. | linear expansion. |
| D. | none of these. |
| Answer» B. pressure rise with temperature. | |
| 538. |
A bolometer is |
| A. | used for the measurement of thermal radiation. |
| B. | an element which senses optical input and delivers thermal output. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 539. |
A barometer measures the __________ pressure. |
| A. | absolute |
| B. | gauge |
| C. | absolute as well as gauge |
| D. | dynamic |
| Answer» B. gauge | |
| 540. |
High temperature of around 2000°C of incandescent gas mantles is measured by a/an$ |
| A. | specially designed thermocouple. |
| B. | optical pyrometer. |
| C. | radiation pyrometer. |
| D. | none of these. |
| Answer» D. none of these. | |
| 541. |
Strain gage uses an electrical conductor wire, which when elastically stretched increases in length and reduces in diameter. Both these dimensional changes result in __________ in the electrical resistance of the wire. |
| A. | no change |
| B. | decrease |
| C. | increase |
| D. | exponential decrease |
| Answer» D. exponential decrease | |
| 542. |
Which of the following shows maximum dip effect (indicating reverse direction of temperature change) ? |
| A. | Mercury thermometer |
| B. | Radiation pyrometer |
| C. | Bimetallic thermometer |
| D. | Thermocouple |
| Answer» B. Radiation pyrometer | |
| 543. |
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 | |
| 544. |
A stable system is the one |
| A. | for which the output response is bounded for all bounded input. |
| B. | which exhibits an unbounded response to a bounded input |
| C. | which satisfies the conditions for a servo problem. |
| D. | none of these. |
| Answer» B. which exhibits an unbounded response to a bounded input | |
| 545. |
Emission spectroscopy is used for |
| A. | solids and metal analysis. |
| B. | determining water purity. |
| C. | determination of CO2 in gases. |
| D. | NOxdetermination. |
| Answer» B. determining water purity. | |
| 546. |
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 | |
| 547. |
Identify an unbounded input from inputs whose transfer functions are given below |
| A. | 1 |
| B. | 1/S |
| C. | 1/S2 |
| D. | 1/(S2 + 1) |
| Answer» D. 1/(S2 + 1) | |
| 548. |
Which of the following is not a composition measuring instrument ? |
| A. | Thermal conductivity cell |
| B. | Mass spectrometer |
| C. | Polarograph |
| D. | Hot wire anemometer |
| Answer» E. | |
| 549. |
Temperature measurement by optical pyrometer is done above __________ point, which is 1063°C.$ |
| A. | antimony |
| B. | gold |
| C. | silver |
| D. | nickel |
| Answer» C. silver | |
| 550. |
Normal mercury thermometer can be used to measure a temperature of about 300°C. However, its maximum temperature measurement range can be increased upto about 500°C by$ |
| A. | filling nitrogen under pressure in the stem. |
| B. | increasing the diameter of the tube. |
| C. | using steel tube in place of glass tube. |
| D. | accounting for the tube expansion. |
| Answer» B. increasing the diameter of the tube. | |