Advertisements
Advertisements
प्रश्न
If water be used to construct a barometer, what would be the height of water column at standard atmospheric pressure (76 cm of mercury) ?
Advertisements
उत्तर
Case: When water is used in a barometer instead of mercury
Pressure exerted by 76 cm of mercury column, P = 76 × 13.6 × g dyn/cm2
Density of water, \[\rho_w\] = 103 kg/m3
\[ \therefore 76 \times 13 . 6 \times g = h \times \rho_\text{w} \times g\]
\[ \Rightarrow \text{h} = \frac{76 \times 13 . 6}{1}\]
\[ \Rightarrow \text{ h } = 1033 . 6 \text{ cm }\]
APPEARS IN
संबंधित प्रश्न
During blood transfusion the needle is inserted in a vein where the gauge pressure is 2000 Pa. At what height must the blood container be placed so that blood may just enter the vein? [Use the density of whole blood from Table 10.1].
A satellite revolves round the earth. Air pressure inside the satellite is maintained at 76 cm of mercury. What will be the height of mercury column in a barometer tube 1 m long placed in the satellite?
Consider the barometer shown in the following figure. If a small hole is made at a point P in the barometer tube, will the mercury come out from this hole?
The three vessels shown in the following figure have same base area. Equal volumes of a liquid are poured in the three vessels. The force on the base will be
Shows in the following figure a siphon. The liquid shown is water. The pressure difference PB − PAbetween the points A and B is
Suppose the pressure at the surface of mercury in a barometer tube is P1 and the pressure at the surface of mercury in the cup is P2.
A barometer kept in an elevator accelerating upward reads 76 cm. The air pressure in the elevator is
Figure shows a capillary tube of radius r dipped into water. If the atmospheric pressure is P0, the pressure at point A is
The surface of water in a water tank on the top of a house is 4 m above the tap level. Find the pressure of water at the tap when the tap is closed. Is it necessary to specify that the tap is closed?
The heights of mercury surfaces in the two arms of the manometer shown in figure are 2 cm and 8 cm.
Atmospheric pressure = 1.01 × 105 N−2. Find (a) the pressure of the gas in the cylinder and (b) the pressure of mercury at the bottom of the U tube.
The area of cross section of the wider tube shown in figure is 900 cm2. If the boy standing on the piston weighs 45 kg, find the difference in the levels of water in the two tubes.
A closed vessel is half filled with water. There is a hole near the top of the vessel and air is pumped out from this hole.
(a) The water level will rise up in the vessel.
(b) The pressure at the surface of the water will decrease
(c) The force by the water on the bottom of the vessel will decrease
(d) The density of the liquid will decrease
Suppose the glass of the previous problem is covered by a jar and the air inside the jar is completely pumped out. (a) What will be the answers to the problem? (b) Show that the answers do not change if a glass of different shape is used provided the height, the bottom area and the volume are unchanged.
Water is filled in a rectangular tank of size 3 m × 2 m × 1 m. (a) Find the total force exerted by the water on the bottom surface on the tank. (b) Consider a vertical side of area 2 m × 1 m. Take a horizontal strip of width δx metre in this side, situated at a depth of x metre from the surface of water. Find the force by the water on this strip. (c) Find the torque of the force calculate in part (b) about the bottom edge of this side.
(d) Find the total force by the water on this side.
(e) Find the total torque by the water on the side about the bottom edge. Neglect the atmospheric pressure and take g = 10 ms−2.
A U-tube containing a liquid is accelerated horizontally with a constant acceleration a0. If the separation between the vertical limbs is l, find the difference in the heights of the liquid in the two arms.
Water leaks out from an open tank through a hole of area 2 mm2 in the bottom. Suppose water is filled up to a height of 80 cm and the area of cross section of the tanks is 0.4 m2. The pressure at the open surface and at the hole are equal to the atmospheric pressure. Neglect the small velocity of the water near the open surface in the tank. (a) Find the initial speed of water coming out of the hole. (b) Find the speed of water coming out when half of water has leaked out. (c) Find the volume of eater leaked out using a time interval dt after the height remained is h. Thus find the decrease in height dh in terms of h and dt.
(d) From the result of park (c) find the time required for half of the water to leak out.
Pressure decreases as one ascends the atmosphere. If the density of air is ρ, what is the change in pressure dp over a differential height dh?
A glass capillary sealed at the upper end is of length 0.11 m and internal diameter 2 × 10-5 m. This tube is immersed vertically into a liquid of surface tension 5.06 × 10-2 N/m. When the length x × 10-2 m of the tube is immersed in liquid then the liquid level inside and outside the capillary tube becomes the same, then the value of x is ______ m. (Assume atmospheric pressure is 1.01 × 105 `"N"/"m"^2`)
