Pressure difference between two points in vessels, pipelines or in two different pipelines can be measured by a differential manometer. The pressure difference measured as the mm of water coloumn in case of mercury-water, differential manometer is equal to (where, H = difference in height of mercury column in mm).

A Differential manometer is connected at the points A and Bat the centre of two pipes. The pipe A(left limb) contains a liquid of specific gravity = 1.5 while pipe B (right limb)contains a liquid of specific gravity 0.85. The pressure at A and B are .5 kgf/cm2 and 1.2 kgf/cm2 respectively. Find the difference in level of mercuru in the differential manometer. A is 2.5m above B and 5 m above the mercury in its own limb. B is 2.5 m above the mercury level in limb A.

A

12.7 cm

B

contains a liquid of specific gravity = 1.5 while pipe B (right lim[contains a liquid of specific gravity 0.85. The pressure at A and B are .5 kgf/cm2 and 1.2 kgf/cm2 respectively. Find the difference in level of mercuru in the differential manometer. A is 2.5m above B and 5 m above the mercury in its own limb. B is 2.5 m above the mercury level in limb A. a) 12.7 cm [ 25.5 cm

C

6.28 cm

D

10.85 cm

A mercury (specific gravity = 13.6) manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be __________ cms.

A

17

B

42

C

84

D

1.8

A student wants to find the absolute pressure of water at a point below the surface of water. He has a barometer and a manometer pressure gauge. The barometer reads 1.3152 bar where as the manometer pressure gauge reads 0.3152 bar. What is the absolute pressure? (Assume that pressure at one end of the manometer is atmospheric.)

A

1 bar

B

1.6304 bar

C

0.3152 bar

D

1.3152 bar

Working principle of manometer comprises of balancing a coloumn of liquid against the pressure to be measured. Inclined tube manometer is especially used for the measurement of __________ pressure.

A

Small differential

B

Atmospheric

C

Absolute

D

Gage

The right limb of a simple U-tube manometer containing mercury is open to the atmosphere while the lift limb is connected to a pipe in which a fluid of specific gravity 0.85 is flowing. The centre of the pipe is 14 cm below the level of mercury in the right limb.Evaluate the pressure of fluid flowing in the pipe if the difference of mercury level in the two limbs is 22 cm.

A

2.86 N/cm2

B

5.73 N/cm2

C

1.43 N/cm2

D

None of the mentioned

The figure below shows water flowing through a pipe. The pressure difference between points P and Q measured using a water-over-mercury manometer is

A

ρ2gH

B

ρ1gH

C

(ρ2 - ρ1) gH

D

(ρ2 - ρ1) gH

Ordinary mercury in glass thermometer is used for measuring temperature upto 120°C. However, for measuring higher temperature upto __________ °C, thermometer is made by filling nitrogen under pressure above the mercury, which stops the evaporation of mercury and reduces the chance of broken thread of mercury.

A

250

B

350

C

550

D

700

The coefficient of volumetric expansion of mercury is 18×10-5/°C. The thermometer bulb has a volume of 10-6 m3 and cross-section of the stem is 0.002cm2. Assuming that bulb is filled with mercury at 0°C, the increase in length of the mercury column at 100°C will be ___________

A

9cm

B

9mm

C

18cm

D

18mm

A U-tube manometer is open at one end and has a gas at the other end if the level of the mercury in both legs of the manometer is equal then what is the temperature of the gas?

A

1 Pa

B

1 Torr

C

1 mm Hg

In a U-tube mercury manometer, one end is exposed to the atmosphere and the other end is connected to a pressurized gas. The gauge pressure of the gas is found to be 40 kPa. Now, we change the manometric fluid to water. The height difference changes by: (ρmercury = 13600 kg/m3, ρwater = 1000 kg/m3).

A

1260%

B

92.64 %

C

Remains unchanged (0%)

D

13.6%