CLASS: B.Sc. PHYSICS
13A / 257
St. JOSEPH’S COLLEGE (AUTONOMOUS) TIRUCHIRAPPALLI – 620 002
SEMESTER EXAMINATIONS – APRIL 2013
TIME: 3 Hrs.
MAXIMUM MARKS: 100
SEM
SET
PAPER CODE
TITLE OF THE PAPER
IV
2011
11UPH430301A
INSTRUMENTATION
SECTION – A
Answer all the questions:
20 x 1 = 20
Choose the correct answer:
1.
________ is defined as the maximum distance or angle through which any part of the
mechanical system may be moved in one direction without causing motion of the next
part
a) Dead band
b) Backlash
c) Drift
d) Linearity
2.
Which of the following is a capacitive type transducer?
a) Magnetostrictive transducer
b) Gap-change type transducer
c) Electrodynamic transducer
d) Proximity type transducer
3.
Pneumatic load cell can be used to measure the force upto ______.
a) 20kN
b) 40kN
c) 60kN
d) 80kN
4.
______ is used to measure the pressure ranging from 10-8 to 10-2 Torr.
a) McLeod Gage
b) Pirani Gage
c) Ionisation Gage
d) Knudsen Gage
5.
Which is the flow meter where the pressure drop remains nearly constant but the area changes?
a) Pitot tube
b) Venturimeter
c) Rotameter
d) Orifice meter
Fill in the blanks:
6.
7.
8.
9.
10.
The ratio of the change of output to the change in input is the ________of the instrument.
________is a self generating type of transducer.
Carrier amplifiers can be used for dc voltages and for ac signals upto a frequency of about
________of the chopper frequency.
________thermometer is not suitable if the temperature changes are rapid.
The flow meter that is independent of fluid density is ________meter.
State True or False:
11.
12.
13.
14.
15.
The maximum power can be transmitted from a device if the impedance of the external load
just matches its internal impedance.
The magnetic type of encoder is also of non-contact type.
An optical interferometer is useful for measuring extremely small motions.
In a cistern type manometer, the ratio of cross sectional areas of well and the tube is not the
factor that determines the scale of the manometer.
In sound power level, the reference power is 1012 W.
Answer in one or two sentences:
16.
17.
18.
19.
20.
Define resolution.
Mention any two main advantages of a digital transducer.
Give the principle of piezo-electric transducer.
Write down any two desirable characteristics of manometer.
List out any two factors on which the rate of cooling of hot wire anemometer depends.
SECTION – B
Answer all the questions:
21.
a.
5 x 4= 20
Write a short note on hysteresis.
OR
22.
b.
Explain the following errors:
i) Systematic error
ii) Instrument error
iii) Loading errors.
a.
Draw and describe the construction of electromagnetic frequency domain transducer.
OR
23.
b.
Draw and explain the construction of unbounded Strain Gage.
a.
With a neat diagram explain the working of pneumatic load cell.
OR
24.
b.
How is an optical amplifying element used to measure the angular displacement?
a.
State and explain the (i) Law of intermediate temperatures
(ii) Law of intermediate metals.
OR
25.
b.
How will you measure the static pressure using Cistern type manometer?
a.
Give reasons for using laser beam in place of monochromatic light in Laser Doppler
Anemometer.
OR
b.
Give the pictorial representation of sound pressure levels of some common sounds.
SECTION – C
Answer any FOUR questions:
26.
4 x 15 = 60
(i) With a neat block diagram explain the basic and auxiliary
elements of a measurement system. (10)
functional
(ii) Derive an expression for the propagation uncertainties in
quantities. (5)
compound
27.
Explain with a neat diagram the non-self generating inductive type of transducers.
28.
(i) With a neat diagram explain the working of potentiometric type
(ii) Derive an expression for fringe spacing using Moire fringe
suitable diagram. (8)
29.
(i) How will you measure the low pressure of a gas by McLeod
(ii) With a neat sketch explain the construction and the working of
pyrometer. (8)
30.
(i) List out the advantages and the limitations of using Pitot Static
(ii) Explain with a neat diagram, the schematic construction of a
microphone. Mention its uses. (7)
**************
of A/D converter. (7)
method with a
Gage device? (7)
selective radiation
tube. (8)
condenser
type