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Chemical Engineering :: Process Control and Instrumentation

  1. A typical example of a physical system with under damped characteristic is a

  2. A.
    U-tube manometer.
    B.
    spring loaded diaphragm valve.
    C.
    CSTR with first order reaction.
    D.
    thermocouple kept immersed in a liquid filled thermowell.

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  3. An aneroid barometer measures the __________ pressure.

  4. A.
    atmospheric
    B.
    absolute
    C.
    vacuum
    D.
    gage

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  5. A bolometer is

  6. 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).

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  7. Thermal wells are used in the temperature measurement to

  8. A.
    guard against corrosive and oxidising action on thermocouple materials
    B.
    reduce measuring lag.
    C.
    increase the fidelity.
    D.
    increase the sensitivity.

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  9. The offset introduced by proportional controller with gain Kcin response of first order system can be reduced by

  10. A.
    reducing value of Kc.
    B.
    introducing integral control.
    C.
    introducing derivative control.
    D.
    none of the above.

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  11. A system with a double pole at the origin is unstable since the corresponding term in the time domain

  12. A.
    is a constant.
    B.
    grows exponentially with time.
    C.
    grows linearly with time.
    D.
    decays linearly with time.

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  13. To increase the speed of response of a pressure spring liquid or gas expansion thermometer, the clearance space between the thermometer bulb and the thermal well should not be filled with

  14. A.
    air
    B.
    a metal powder or graphite
    C.
    oil
    D.
    mercury

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  15. In a second order under damped system, the

  16. A.
    time required for the response of first reach its ultimate value is called the response time.
    B.
    overshoot (which is a measure of how much the response exceeds the ultimate value) increase with the decrease of damping co-efficient e.
    C.
    decay ratio (which is the ratio of the sizes of successive peaks) is equal to the reciprocal of overshoot.
    D.
    characteristics of a step response is represented by

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  17. In an exothermic chemical reactor, the manipulated variable is the flow rate of

  18. A.
    coolant
    B.
    reactants
    C.
    product
    D.
    none of these

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  19. Very low pressure is expressed in microns(μ), which is equal to __________ mm of Hg coloumn (absolute) at 0°C.

  20. A.
    0.0001
    B.
    0.001
    C.
    0.01
    D.
    0.1

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