Differential Manometer

Q. An inverted U-tube manometer is used to measure the pressure difference between two pipes A and B, as shown in the figure. Pipe A is carrying oil(specific gravity=0.8) and pipe B is carrying water. The densities of air and water are 1.16 kg/$m^3$ and 1000 kg/$m^3$, respectively. The pressure difference between pipes A and B is _____kPa.
Acceleration due to gravity:g = 10 m/$s^2$

1. -2.199

Q. The difference in pressure head, measured by a mercury water differential manometer for a 20 cm difference of mercury head will be

1. 2.72 m
2. 2.52 m
3. 2.0 m
4. 0.2 m

Q. A mercury manometer is used to measure the static pressure at a point in a water pipe as shown in figure. The level difference of mercury in the two limbs is 10 mm. The gauge pressure at that point is

1. 1236 Pa
2. 1333 Pa
3. Zero
4. 98 Pa

Q. Refer to figure, the absolute pressure of gas A in the bulb is

1. 771.2 mm Hg
2. 752.65 mm Hg
3. 767.35 mm Hg
4. 748.8 mm Hg

Q. In the set-up shown in the given figure, assuming the specific weight of water as 10, 000 N/$m^3$, the pressure difference between the points A and B will be

1. 10 N/$m^2$
2. -10 N/$m^2$
3. 20 N/$m^2$
4. -20 N/$m^2$

Q.

Why should the Barometric Pressure be corrected for the vapor pressure of water?

Q. In the inclined manometer shown in the figure below, the reservoir is large. Its surface may be assumed to remain at a fixed elevation. A is connected to a gas pipeline and the deflection noted on the inclined glass tube is 100mm Assuming $\theta ={30}^{\circ }$ and the manometric fluid as oil with specific gravity of 0.86, the pressure at A is

1. 43 mm water (vacuum)
2. 43 mm water
3. 86 mm water
4. 100 mm water

Q. The cross-sectional area of one limb of a U-tube manometer (figure shown below) is made 500 times larger than the other, so that the pressure difference between the two limbs can be determined by measuring h on one limb of the manometer. The percentage error involved is

1. 1.0
2. 0.5
3. 0.2
4. 0.05

Q. Multi U-tube manometers with different fluids are used to measure

1. low pressures
2. medium pressures
3. high pressures
4. very low pressures

Q. Figure below shows U-Tube manometer used to measure absolute pressure of the gas in the bulb centre "O". Mercury and water are immiscible liquids. At this unknown pressure of gas at O, the interface between the liquids is at the bottom most point of the U-Tube. Ignore the size of tube and radius of curvature of liquids (meniscus effects & capillarity effects). The height of mercury column is given as 75 cm. The pressure of gas at O is : (Neglect gas column since gas is of lower density).

1. 89.5 kPa vaccum
2. 10.5 kPa absolute
3. both of these
4. none of these

Q.

Atmospheric pressure recorded by a simple barometer is 75 cm of mercury. The atmospheric pressure in pascal is: (g = 9.8m/s²)

1. 99900 Pa

2. 99990 Pa

3. 99960 Pa

4. 99999 Pa