The unit of ‘time constant’ of a system is the same as that of___________________?

Related Mcqs:

1. 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

2. Hot wire anemometer is used for the measurement of___________________?

   A. Flow rates of fluids
   B. Flow rates of granular solids
   C. Very high temperature
   D. Thermal conductivity of gases

3. 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

4. The time constant of a first order process with resistance R and capacitance C is__________________?

   A. R + C
   B. R – C
   C. RC
   D. 1/RC

5. Helium gas constant volume thermometer is suitable for the measurement of a temperature of ______________ °C?

   A. < 100
   B. < 0
   C. > 0
   D. > 800

6. Range of hydrogen gas constant volume thermometer is _____________ °C?

   A. -10 to 20
   B. 0 to 100
   C. 100 – 500
   D. 400 – 1000

7. 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. e-ηS
   B. (T1S + 1)/(T2S + 1)
   C. (T1S/(T2S + 1)
   D. (T1S + 1)/(T2S

8. Sub-zero temperature (< 0°C) can be measured by a constant volume gas thermometer employing ?

   A. Helium
   B. Nitrogen
   C. Hydrogen
   D. None of these

9. A first order system with unity gain and time constant η is subjected to a sinusoidal input of frequency w = 1/η. The amplitude ratio for this system is______________?

   A. 1
   B. 0.5
   C. 1/√2
   D. 0.25

10. 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