Pressure vs Velocity

Q.

Does pressure increase with temperature?

Q.

At absolute zero temperature, pressure of a gas will be

1. Zero

2. One atmospheric pressure

3. 

4. 

Q.

An air bubble of radius 2.0 mm is formed at the bottom of a 3.3 m deep river. Calculate the radius of the bubble as it comes to the surface. Atmospheric pressure $=1.0\times {10}^5$ Pa and density of water $=1000kg{m}^{-3}$

1. 2.2mm

2. 1.8mm

3. 2mm

4. 2.8mm

Q.

What is the density of carbon dioxide gas at the temperature 400k and 0.0821 atmospheric pressure?

Q.

For a diatomic gas change in internal energy for unit change in temperature at constant pressure and constant volume are $U_1$ and $U_2$ respectively. $U_1:U_2$ is

1. 5 : 3

2. 3 : 5

3. 1 : 1

4. 5 : 7

Q.

If the mean free path of atoms is doubled then the pressure (P) of gas will become

1. P/4

2. P/2

3. P/8

4. P

Q. 28. A particle of mass m oscillates along the horizontal diameter AB inside a smooth spherical shell of radius R. At any instant kinetic energy is K. Then force applied by particle on the shell at that instant

Q.

A box contains n molecules of a gas. How will the pressure of the gas be effected, if the number of molecules is made 2n

1. Pressure will decrease

2. Pressure will be doubled

3. Pressure will become three times

4. Pressure will remain unchanged

Q.

A vessel contains 14 g of hydrogen and 96 g of oxygen at STP. Chemical reaction is induced by passing electric spark in the vessel till one of the gases is consumed. The temperature is brought back to its starting value 273 K. Find the pressure in the vessel.

1. 0.3 atm

2. 0.2atm

3. 0.1 atm

4. 0.4 atm

Q.

Figure shows a vertical cylindrical vessel separated in two parts by a frictionless piston free to move along the length of the vessel. The length of the cylinder is 90 cm and the piston divides the cylinder in the ratio of 5:4. Each of the two parts of the vessel contains 0.1 mole of an ideal gas. The temperature of the gas is 300 K in each part. Calculate the mass of the piston

1. 15.5 kg

2. 5.7 kg

3. 12.7 kg

4. 10.3 kg

Q. Air is filled in a bottle and it is corked at 35 degree celsius. If the cork can come out at 3 atmospheric pressure then upto what temperature should the bottle be heated in order to rempove the cork

Q.

A beam of hydrogen molecules is directed toward a wall, at an angle ${32}^{\circ }$ with the normal to the wall. Each molecule in the beam has a speed of 1.0 km/s and a mass of $3.3\times {10}^{24}g$. The beam strikes the wall over an area of $2.0C{m}^2$, at a rate of $4.0\times {10}^{23}$ molecules per second. What is the beam's pressure on the wall?

1. 9 kPa

2. 11 kPa

3. 1 kPa

4. 13 kPa

Q.

Assume that the temperature remains essentially constant in the upper part of the atmosphere. Obtain an expression for the variation in pressure with height in the upper atmosphere. The mean molecular weight of air is M. Assume a variable $P_O$ for the pressure at a height h = 0, where h = 0 depends on the choice of origin (could very well be at the beginning of the stratosphere, for example).

1. 

2. 

3. 

4. .

Q.

Two containers of equal volume contain the same gas at pressures $P_1$ and $P_2$ and absolute temperatures $T_1$ and $T_2$ respectively. On joining the vessels, the gas reaches a common pressure P and common temperature T. The ratio $\frac{P}{T}$ is equal to

1. 

2. 

3. 

4. 

Q.

At a given tempreture, the pressure of an ideal gas of density $\rho$ is proportional to

1. 

2. 

3. 

4. 

Q. Each molecule of mass $m$ of a monoatomic gas has got three degrees of freedom. The r.m.s. velocity of these molecules is $v$ at temperature $T$. For a diatomic molecule of mass $m$ and temperature $T$ which has got five degrees of freedom, r.m.s. velocity of molecule is

1. $\sqrt{\frac{5}{3}}v$
2. $\sqrt{\frac{3}{5}}v$
3. $v$
4. None of these

Q. The density of an ideal gas is $6\times {10}^{-2}{\text{kg/m}}^3$ and the root mean square velocity of the gas molecules is $500\text{m/s}$. The pressure exerted by the gas on the walls of the vessel is

1. $5\times {10}^3{\text{N/m}}^2$
2. $1.2\times {10}^{-4}{\text{N/m}}^2$
3. $0.75\times {10}^{-4}{\text{N/m}}^2$
4. $40{\text{N/m}}^2$

Q.

The relation between the gas pressure P and average kinetic energy per unit volume E is

1. 

2. 

3. 

4. 

Q.

Pressure is exerted by a gas on the walls of the container because

1. It loses kinetic energy

2. It sticks with the walls

3. On collision with the walls there is a change in momentum

4. It is accelerated towards the walls

Q. 7. The mean free path of a molecule of He gas is . Its mean free path along any arbitrary coordinate axis will be OC 2 3 (4) 3

Q.

The Bat Life: What can be said with 100% confidence about the temperatures at point $P_{1}and{P}_2$?

1. >

2. <

3. 

4. .

Q. A bullet of mass 10 g moving with a speed of20 ms hits an ice block of mass 990 g kept ona frictionless floor and gets stuck in it How muchice, will melt if 50% of the lost KE goes to ice?(initial temperature of the ice block and

Q.

At absolute zero temperature, pressure of a gas will be

1. Zero

2. One atmospheric pressure

3. $P_0\times 273$

4. $P_0\times 76$

Q.

Why does gas exert pressure?

Q.

Figure shows a vertical cylindrical vessel separated in two parts by a frictionless piston free to move along the length of the vessel. The length of the cylinder is 90 cm and the piston divides the cylinder in the ratio of 5:4. Each of the two parts of the vessel contains 0.1 mole of an ideal gas. The temperature of the gas is 300 K in each part. Calculate the mass of the piston

1. 10.3 kg

2. 5.7 kg

3. 12.7 kg

4. 15.5 kg

Q.

At a given tempreture, the pressure of an ideal gas of density $\rho$ is proportional to

1. $\frac{1}{{\rho }^2}$

2. $\frac{1}{\rho }$

3. ${\rho }^2$

4. $\rho$

Q. 45. A horizontal force 3Mg/8 is applied at the top most of a cylinder of mass M , length 2R and radius R as shown . If the cylinder remains at rest, distance of line of action of normal reaction from axis of cylinder is?

Q.

Two glass bulbs of equal volumes connected by a narrow tube are filled with a gas at $0^{\circ }C$ and a pressure of 76 cms of Hg. One of the bulbs is then placed in a water bath maintained at ${62}^{\circ }C$. What is the new value of the pressure inside the bulb? The volume of connecting tube is negligible

1. 80 cm of Hg

2. 87.2 cm of Hg

3. 83.8 cm of Hg

4. 78.5 cm of Hg

Q.

The Bat Life: To monitor the pressure of helium in the canister, Batman had placed 2 sensors which sense pressure and temperature at points $P_{1}and{P}_2$. When the piston was in motion, Batman's suit registered an error in the canister. When he analysed the error back in the Batcave he noticed that the pressure at points $P_{1}and{P}_2$ were different. Which amongst the following statements is true?

1. The sensors which detect the pressure at points are faulty. A gas confined within a single boundary cannot have twovalues of pressure

2. The sensors need not necessarily be faulty, as the gas is not in equilibrium.

Q. The molecules of a given mass of gas has r.m.s speed $400\text{m/s}$ at ${27}^{\circ }\text{C}$ and ${10}^5{\text{N/m}}^2$ pressure . When the absolute temperature is doubled and the pressure is halved, the r.m.s. speed of the molecules of the same gas is

1. $400\text{m/s}$
2. $200\sqrt{2}\text{m/s}$
3. $400\sqrt{2}\text{m/s}$
4. $1200\text{m/s}$