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Chemical Engineering :: Process Control and Instrumentation

  1. Which of the following is not a mechanical pressure sensing element ?

  2. A.
    Bellows
    B.
    Diaphragm
    C.
    Bourdon tube
    D.
    U-tube

  3. __________ are analysed using a polarograph.

  4. A.
    Isotonic solutions
    B.
    Solids
    C.
    Liquids
    D.
    Gases

  5. Which of the following judges the accuracy of an instrument ?

  6. A.
    Dead zone
    B.
    Drift
    C.
    Static error
    D.
    None of these

  7. On-off controllers are normally used for

  8. A.
    low loads
    B.
    temperature changes
    C.
    flow rate changes
    D.
    none of these

  9. Magnetic flowmeters are generally not used for the velocity/flow measurement of hydrocarbons due to their

  10. A.
    low thermal conductivity.
    B.
    low electrical conductivity.
    C.
    high viscosity index.
    D.
    low flash point.

  11. Which of the following controllers has maximum offset ?

  12. A.
    P-controller
    B.
    P-I controller
    C.
    P-D controller
    D.
    P-I-D controller

  13. Pressure of 0.01 psi (absolute) can be measured by __________ gauge.

  14. A.
    ionisation
    B.
    Pirani
    C.
    Mcloid
    D.
    none of these

  15. High temperature of around 2000°C of incandescent gas mantles is measured by a/an

  16. A.
    specially designed thermocouple.
    B.
    optical pyrometer.
    C.
    radiation pyrometer.
    D.
    none of these.

  17. The unit step response of the transfer function 1/(s2 + 2s + 3)

  18. A.
    has a non-zero slope at the origin.
    B.
    has a damped oscillatory characteristics.
    C.
    is overdamped
    D.
    is unstable

  19. 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