246 MECHANICAL ENGINEERING PRINCIPLES
In questions 14 to 18 select the most
suitable pressure-indicating device from
the following list:
(a) Mercury filled U-tube manometer
(b) Bourdon gauge
(c) McLeod gauge
(d) aneroid barometer
(e) Pirani gauge
(f) Fortin barometer
(g) water-filled inclined barometer
- A robust device to measure high pres-
sures in the range 0–30 MPa. - Calibration of a Pirani gauge.
- Measurement of gas pressures compara-
ble with atmospheric pressure. - To measure pressures of the order of
1 MPa. - Measurement of atmospheric pressure to
a high degree of accuracy. - Figure 21.7(b), on page 238, shows a
U-tube manometer connected to a gas
under pressure. If atmospheric pressure
is 76 cm of mercury andh 1 is measured
in centimetres then the gauge pressure
(in cm of mercury) of the gas is:
(a)h 1 (b)h 1 + 76
(c)h 1 −76 (d) 76−h 1
- In question 19 the absolute pressure of
the gas (in cm of mercury) is:
(a)h 1 (b)h 1 + 76
(c)h 1 −76 (d) 76−h 1
- Which of the following statements is
true?
(a) Atmospheric pressure of 101.325
kN/m^2 is equivalent to 101.325
millibars.
(b) An aneroid barometer is used as a
standard for calibration purposes.
(c) In engineering, ‘pressure’ is the
force per unit area exerted by
fluids.
(d) Water is normally used in a barom-
eter to measure atmospheric pres-
sure.
- Which of the following statements is
true for a ship floating in equilibrium?
(a) The weight is larger than the buoy-
ancy.
(b) The weight is smaller than the
buoyancy.
(c) The weight is equal to the buoy-
ancy.
(d) The weight is independent of the
buoyancy.
- For a ship to be initially stable, the
metacentric height must be:
(a) positive (b) negative
(c) zero (d) equal to the buoyancy
- For a ship to be stable, it is helpful if
KGis:
(a) negative (b) large
(c) small (d) equal toKM