Pressure and Temperature

Q. A gas is confined in a chamber of constant volume. When the chamber is immersed in a bath of melting ice, the pressure of the gas is 1000 torr. The final temperature, when the pressure in the manometer indicates an absolute pressure of 400 torr is:

1. $109\text{K}$
2. $273\text{K}$
3. $373\text{K}$
4. $0\text{K}$

Q. The figure given below shows a mercury barometer, with some air trapped in the tube. Atmospheric pressure is given as 101, 000 Pa. Find the pressure of the trapped gas. Given, density of mercury = 13600 kg/m${}^3$.

1. $P_{air}$ = 37820 Pa
2. $P_{air}$ = 16965 Pa
3. $P_{air}$ = 72966 Pa
4. $P_{air}$ = 27696 Pa

Q. A tube of length 1 m is completely filled with mercury and is inverted in a mercury cup for constructing a barometer which reads 76 cm. Suppose a 1 m tube is filled with mercury upto 76 cm and closed by the cork.
It is inverted into a tray containing mercury and the cork is opened. The height of mercury column now in the tube over the surface of mercury in the tray will be:

1. 76 cm
2. Zero
3. >76 cm
4. <76 cm

Q. Height of a mercury column is given as 76 cm of Hg in a barometer. Find the height of the column of a liquid of density 1.2 g/cc would be neccessary to balance atmospheric pressure
Given: Density of mercury = 13600 kg/$m^3$

1. 546.8 cm
2. 861.3 cm
3. 432.5 cm
4. 742.6 cm

Q. The lengths of air column are 10 cm and 8 cm in a faulty barometer when it reads 72 and 71 cm of Hg. The value of atmospheric pressure is:

1. 71.5 cm of Hg
2. 68 cm of Hg
3. 76 cm of Hg
4. 74 cm of Hg

Q.

A manometer is connected to a flask containing a gas. The open arm reads 36.2 cm whereas the arm connected to the flask reads 15.5 cm. If the barometric pressure is 743 mm Hg, the gas pressure in atm is?

1. 1.0 atm
2. 1.25 atm
3. 1.30 atm
4. 1.45 atm
   

Q. If the atmospheric pressure in a housing area is ${10}^5$Pa. What is the magnitude of the force exerted by the atmospheric gas on a flat horizontal roof of dimensions $5m\times 4m$?

1. $2\times {10}^7$ N
2. $2\times {10}^6$ N
3. $4\times {10}^6$ N
4. $8\times {10}^6$ N

Q. When a bubble containing ideal gas rises from the bottom of a lake to the surface, its radius doubles. If atmospheric pressure is equal to that of a column of water height H, then the depth of lake is:

1. H
2. 2H
3. 7H
4. 8H

Q. If the mercury in the barometer is replaced by water, What will be the resulting height of the water column?
Given: Density of water = $1000kg{m}^3$, Density of mercury = $13600kg{m}^3$

1. $0.76m$
2. $10.3m$
3. $11.2m$
4. $9.8m$

Q. A gas cylinder containing cooking gas can withstand a pressure 14.9 atmosphere. The pressure guage of the cylinder indicates 12 atmosphere at ${27}^{\circ }\text{C}$. Due to a sudden fire in the building, the temperature starts rising. Find the temperature ( K) when the cylinder explodes?

Q. If the atmospheric pressure in a housing area is ${10}^5$Pa. What is the magnitude of the force exerted by the atmospheric gas on a flat horizontal roof of dimensions $5m\times 4m$?

1. $2\times {10}^7$ N
2. $2\times {10}^6$ N
3. $4\times {10}^6$ N
4. $8\times {10}^6$ N

Q. A gas is confined in a chamber of constant volume. When the chamber is immersed in a bath of melting ice, the pressure of the gas is 1000 torr. The final temperature, when the pressure in the manometer indicates an absolute pressure of 400 torr is:

1. $109\text{K}$
2. $273\text{K}$
3. $373\text{K}$
4. $0\text{K}$

Q. A tube of length 1 m is completely filled with mercury and is inverted in a mercury cup for constructing a barometer which reads 76 cm. Suppose a 1 m tube is filled with mercury upto 76 cm and closed by the cork.
It is inverted into a tray containing mercury and the cork is opened. The height of mercury column now in the tube over the surface of mercury in the tray will be:

1. 76 cm
2. Zero
3. >76 cm
4. <76 cm

Q. A manometer is connected to a flask containing a gas. The open arm reads 36.2 cm whereas the arm connected to the Hg, the gas pressure in atm is ?

1. 1.0 atm
2. 1.25 atm
3. 1.30 atm
4. 1.45 atm

Q. As per the figure given below, find the total pressure at the bottom, if the vessel is closed.
Density of liquid 1 = 13.6 $g/cc$
Density of liquid 2 = 5.4 $g/cc$
Density of liquid 3 = 2.5 $g/cc$

(Given $g=9.8m/s^2$)

1. $97.35\text{kPa}$
2. $123.68\text{kPa}$
3. $112.28\text{kPa}$
4. $145.68\text{kPa}$