Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

process ctrl inst > section 5 > Flashcards

section 5 Flashcards

1
Q

Time constant is the
a. time taken by the controlled variable to
reach 63.2% of its full change.
b. same as transportation lag.
c. same as dead time.
d. time required by the measured variable to
reach 63.2% of its ultimate change.

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mercury manometer (U-tube type) exemplifies a
__________ order system.
a. Zero
b. First
c. Second
d. third

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Emf developed by a thermocouple while
measuring a temperature of 400°C is 22 mV. The
type of thermocouple used is
a. Chromel-alumel
b. Iron-constantan
c. Platinum-rhodium
d. platinum-platinum+rhyodium

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bode stability method uses __________ loop
transfer function.
a. Open
b. Closed
c. either (a) or (b)
d. neither (a) nor (b)

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Working principle of bimetallic thermometers is
difference in linear co-efficient of thermal
expansion of two strips of different metals welded
together. Which of the following has the maximum
thermal co-efficient of linear expansion?
a. Nickel
b. Brass
c. Chromel
d. Invar

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which of the following is not a second order
instrument?
a. Mercury in glass thermometer with
covering.
b. Bare mercury in glass thermometer.
c. Pressure gauge with one bellow, two tubes
and a tank.
d. None of these.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

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

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Specific conductance is defined as the reciprocal
of resistance in ohms of 1c.c. of liquid at a specified
temperature. Its value for distilled water is about
__________ micro mho/cm3.
a. 50
b. 100
c. 10
d. 1

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

A simple pitot tube measures the
a. average velocity
b. maximum velocity
c. point velocity
d. static pressure

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

For a feed back control system to be stable, the
a. roots of the characteristic equation should be real.
b. poles of the closed loop transfer function should lie in the left half of the complex plane.
c. Bode plots of the corresponding open loop transfer function should
monotoni-cally decrease.
d. poles of the closed loop transfer function
should lie in the right half of the complex
plane.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A mercury thermometer can not be used to
measure the temperature below the freezing point of
mercury, which is __________ °C.
a. -38.9
b. -11.9
c. -60.9
d. -80.9

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

__________ controller has the maximum stabilizing time.
a. P
b. PD
c. PI
d. PID

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

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.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Stalagmometer is used for the measurement of
a. kinematic viscosity
b. surface tension
c. refractive index
d. optical activity

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The deflection in diaphragm (which is used as
pressure sensor in pneumatic and electronic
instruments) is dependent on the metal thickness, its
diameter (d) and shape & number of corrugations.
Its deflection is proportional to
a. d
b. d2
c. d3
d. d4

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Working principle of radiation pyrometer is
based on the
a. Wien’s law
b. Kirchoffs law
c. stefan-Boltzman law
d. Seebeck effect

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Liquid levels in autoclaves are measured by
a. simple float
b. differential float type manometer
c. glass gauge
d. none of these

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

E.m.f. generated by thermocouples is of the
order of
a. Millivolts
b. Microvolts
c. Volts
d. kilo volts

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A pyrheliometer is an instrument used for
measuring the
a. bright sunshine period.
b. beam radiation.
c. diffuse radiation.
d. none of these.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Flow rate through an orifice is __________ the
pressure differential.
a. proportional to
b. inversely proportional to the square root of
c. proportional to the square root of
d. inversely proportional to the square of

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Thermistors are used in __________ devices.
a. voltage measuring
b. temperature measuring
c. temperature compensating
d. both(b)&(c)

A

d

22
Q

__________ is the static characteristics of an
instrument,
a. Response
b. Tine lag
c. Drift
d. dynamic error

A

c

23
Q

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°

A

c

24
Q

Dead zone in an instrument must be less than
__________ percent of the scale.
a. 0.2
b. 1.5
c. 4
d. 8

A

a

25
Q

Emission spectroscopy is used for
a. solids and metal analysis.
b. determining water purity.
c. determination of CO2 in gases.
d. Nox determination.

A

a

26
Q

Gas analysis is commonly done using the
a. thermal conductivity cell
b. X-ray diffraction
c. mass spectrometer
d. emission spectrometer

A

a

27
Q

The open loop transfer function of a control
system is KR/(1+TS) . This represents
a. a first order system.
b. dead time system.
c. a first order time lag.
d. a second order system.

A

a

28
Q

Thermal conductivity measurement is used for
the determination of
a. O2 percentage in the flue gas.
b. specific gravity of petrofuels.
c. composition of an alloy.
d. CO2 percentage in the flue gas.

A

D

29
Q

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

A

D

30
Q

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

A

c

31
Q

Thermal conductivity cell is the primary
element of a/an __________ analyser.
a. Oxygen
b. carbon dioxide
c. carbon monoxide
d. sulphur dioxide

A

b

32
Q

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.

A

c

33
Q

The root locus method, a pole of a transfer
function G(s) is the value of s for which G(s)
approaches
a. -1
b. 0
c. 1
d. ∞

A

d

34
Q

__________ type of element is normally not
used in the bimetallic thermometers.
a. Flat spiral
b. Bourdon tube
c. Single helix
d. Multiple helix

A

b

35
Q

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

A

b

36
Q

Process degree of freedom indicates
__________ number of controllers to be used.
a. the maximum
b. the minimum
c. both maximum and the minimum
d. nothing about the

A

a

37
Q

Characteristic equation is the denominator of
__________ loop transfer function.
a. Open
b. Closed
c. both (a)and (b)
d. neither (a) nor (b)

A

b

38
Q

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

A

c

39
Q

Polarograph is meant for the analysis of
a. gaseous mixture
b. miscible liquids
c. Solids
d. isotopes

A

c

40
Q

Which of the following fluid flow measuring
devices can measure the largest flow rate?
a. V-notch
b. Rotameter
c. Orifice meter
d. Weir

A

d

41
Q

Flow rate of sludge is not measured by a/an
a. orifice meter
b. open weir
c. Kennison nozzle
d. both(b)&(c)

A

d

42
Q

In a shell and tube heat exchanger, the inlet
temperature of heating/cooling fluid is the
__________ variable.
a. Load
b. Manipulated
c. Controlled
d. none of these

A

a

43
Q

Which of following error integral is considered
as the best criterion in controller settings?
a. ∫ |ee| ∞
0 dddd
b. ∫ |ee| ∞
0 dddd
c. ∫ e2dt
0 dddd
d. none of these

A

c

44
Q

Polarisation of light forms the working principle
of a
a. Polarimeter
b. Polarograph
c. Chromatograph

A

a

45
Q

A bimetallic thermometer as compared to
industrial mercury in glass thermometer has almost
the same
a. temperature measuring range (- 40°C to
450°C).
b. accuracy (± 1% of span).
c. speed of response.
d. all a, b & c.

A

d

46
Q

Thermal wells used in temperature
measurements should have
a. very thick walls.
b. low emissivity.
c. polished surface.
d. high transmissivity of radiation.

A

d

47
Q

Which of the following flow-metering instru-
ments is an areameter?

a. Venturimeter
b. Rotameter
c. Pitot tube
d. Hot wire anemometer

A

b

48
Q

Out of the following thermocouple wire
insulating material, the highest temperature rating is
for
a. Teflon
b. ceramic fibre
c. Asbestos
d. fibre glass

A

b

49
Q

Which is the most suitable instrument for
measuring pressure below 3 microns?
a. Mcleoid gauge
b. Alphatron
c. Ionisation gauge
d. Bourdon guage

A

c

50
Q

Routh stability method uses __________ loop
transfer function.
a. Open
b. Closed
c. either (a) or (b)
d. neither (a) nor (b)

A

b

process ctrl inst (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions