CBSE Questions for Class 11 Engineering Physics Kinetic Theory Quiz 7 - MCQExams.com

'N' molecules each of mass 'm', of gas A and '2N' molecules, each of mass '2m', of gas B are contained in the same vessel. Which is maintained at a temperature T. The mean square of the velocity of molecules of B type is denoted by $$V^{2}$$ and the mean square of the X component of the velocity of A type is denoted by $$\omega^{2}$$, $$\displaystyle\ \frac{\omega^{2}}{V^{2}}=$$
  • 2
  • 1
  • 1/3
  • 2/3
A vessel has 6g of hydrogen at pressure P and temperature 500K. A small hole is made in it so that hydrogen leaks out. How much hydrogen leaks out if the final pressure is $$P/2$$ and temperature falls to 300K?
  • 2g
  • 3g
  • 4g
  • 1g
Graph of specific heat at constant volume for a monatomic gas is:
A graph is plotted with PV/T on y-axis and mass of the gas along x-axis for different gases. The graph is 
  • a straight line parallel to x-axis for all the gases
  • a straight line passing through origin with a slope having a constant value for all the gases
  • a straight line passing through origin with a slope having different values for different gases
  • a straight line parallel to y-axis for all the gases
A gas mixture consists of 2 moles of oxygen and 4 moles of Argon at temperature T. Neglecting all vibrational moles, the total internal energy of the system is 
  • 4RT
  • 15RT
  • 9RT
  • 11RT
If pressure of a gas contained in a closed vessel is increased by 0.4% when heated by $$1^{0}C$$, the initial temperature must be 
  • 250K
  • $$250^{0}C$$
  • 2500K
  • $$25^{0}C$$
An ideal gas is found to obey an additional law $$VP^{2}$$ = constant. The gas is initially at temperature T and volume V. When it expands to a volume 2V, the temperature becomes :
  • $$\displaystyle\ \frac{T}{\sqrt{2}}$$
  • $$2T$$
  • $$\displaystyle\ \frac{2T}{\sqrt{2}}$$
  • $$4T$$
Final volume of the system will be nearly -
  • $$6.2m^{3}$$
  • $$2.8m^{3}$$
  • $$4.5m^{3}$$
  • $$1.4m^{3}$$
The heat capacity at constant volume of a sample of a monoatomic gas is $$35\ J/K$$. Find the number of moles.
  • $$12.81 \ \ mol  $$
  • $$21.81 \ \ mol  $$
  • $$4.81 \ \ mol  $$
  • $$2.81 \ \ mol  $$
If the kinetic energy of the molecules in $$5$$ litres of helium at $$2$$ $$atm$$ is $$E$$. What is the kinetic energy of molecules in $$15$$ litres of oxygen at $$3$$ $$atm$$ in terms of $$E$$?
  • $$7.5E$$
  • $$7E$$
  • $$8.5E$$
  • $$8E$$
The average kinetic energy of the molecules of an ideal gas at $$10^{\circ}C$$ has the value E. The temperature at which the kinetic energy of the same gas becomes 2E is
  • $$5^{\circ}C$$
  • $$10^{\circ}C$$
  • $$40^{\circ}C$$
  • None of these
Choose the wrong options
  • Translation kinetic energy of all ideal gases at same temperature is same
  • In one degree of freedom all ideal gases has internal energy = $$\displaystyle \frac {1}{2}\, RT$$
  • Translational degree of freedom of all ideal gases is three
  • Translational kinetic energy of one mole of all ideal gases is $$\displaystyle \frac{3}{2} RT$$
$$\Delta C_p$$ for change $$N_2(g)+3H_2 (g)= 2N\! H_3(g)$$ is:
  • $$C_{pNH_3}-(C_{pN_2})$$
  • $$2C_{pNH_3}-(C_{pN_2}+3C_{pH_2})$$
  • $$2C_{pNH_3}-(C_{pH_2})$$
  • $$2C_{pNH_3}+(C_{pN_2}+3C_{pH_2})$$
The poisson's ratio for $$O_2$$ is $$1.4$$. Which of the following are correct for $$O_2$$?
  • $$c_{ v } = 5 \ cal \ K^{-1} \ mol^{-1}$$
  • $$C_v = 0.156\  cal\ K^{-1}\ g^{-1}$$
  • $$c_p = \dfrac { R\gamma }{ \gamma - 1 }$$
  • $$c_v = \dfrac { R }{ (\gamma - 1) }$$
When x amount of heat is given to a gas at constant pressure, it performs $$\displaystyle \frac{x}{3}$$ amount of work. The average number of degrees of freedom per molecule of the gas is-
  • 3
  • 4
  • 5
  • 6
At ordinary temperatures, the molecules of a diatomic gas have only translational and rotational kinetic energies. At high temperatures, they may also have vibrational energy. As a result of this compared to lower temperatures, a diatomic gas at higher temperatures will have-
  • lower molar heat capacity
  • higher molar heat capacity
  • lower isothermal compressibility
  • higher isothermal compressibility
Which of the following expands most on the rise of an equal amount of temperature?
  • Liquid
  • Solid
  • Gas
  • Cannot say
A sample of an ideal gas is contained in a cylinder. The volume of the gas is suddenly decreased. A student makes the following statements to explain the change in pressure of the gas.
I. The average kinetic energy of the gas atoms increases.
II. The atoms of the gas hit the walls of the cylinder more frequently.
III. Temperature of the gas remains unchanged.
Which of these statements is true?
  • I and II only
  • I and III only
  • II and III only
  • I, II and III
STATEMENT-1 : According to kinetic theory of gases the internal energy of a given sample of an ideal gas is only kinetic.
STATEMENT-2 : The ideal gas molecules exert force on each other only when they collide.
  • STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1
  • STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1
  • STATEMENT-1 is True, STATEMENT-2 is False
  • STATEMENT-1 is False, STATEMENT-2 is True
When the temperature is increased:
  • speed with which the molecules vibrate increases
  • speed with which the molecules vibrate decreases
  • there is no change in the speed of the molecules
  • the speed of the molecules remains constant
Average value of poisson`s ratio for a mixture of two mol of each gas A and B is $$1.66$$, then
  • gases are mono-atomic
  • gases are diatomic
  • average molar heat capacity at constant volume is $$4 cal$$
  • average molar heat capacity at constant V is $$3 cal$$.
One mole of a diatomic gas undergoes a process $$P=\frac {P_0}{1+\left (\frac {V}{V_0}\right )^3}$$, where $$P_0, V_0$$ are constants. The  translational kinetic energy of the gas when $$V = V_0$$ is given by
  • $$\frac {5P_0V_0}{4}$$
  • $$\frac {3P_0V_0}{4}$$
  • $$\frac {3P_0V_0}{2}$$
  • $$\frac {5P_0V_0}{2}$$
.
304203_a103e1f3423d4fcd913dcfca62def5dd.png
  • 250
  • 500
  • -250
  • -500
A gas behaves more closely like an ideal gas at
  • low pressure and low temperature
  • low pressure and high temperature
  • at all pressure and temperature
  • none of these
If T represents the absolute temperature of an ideal gas, the volume coefficient of thermal expansion at constant pressure is proportional to:
  • T
  • T$$^2$$
  • 1/T
  • 1/T$$^2$$
The poisson`s ratio for $$O_2$$ is $$1.4$$. Which of the following are correct for $$O_2$$?
  • $$C_{ VM } = 5 cal$$
  • $$C_V = 0.156 cal$$
  • $$C_P = \frac { R\Upsilon }{ \Upsilon - 1 }$$
  • $$C_V = \frac { R }{ (\Upsilon - 1) }$$
A certain mass of an ideal gas undergoes a reversible isothermal compression. Its molecules, compared with the initial state, will then have the same
(i) root mean square velocity
(ii) mean momentum
(iii) mean kinetic energy
  • (i), (ii), (iii)
  • (i), (ii)
  • (ii), (iii)
  • (i)
Kinetic energy of the particles:
  • is the energy of the bulk matter
  • decreases with increase in temperature
  • increases with increase in temperature
  • temperature has no effect on kinetic energy
The number of air molecules in a ( 5m x 5m x 4m ) room at standard temperature and pressure is of the order of :
  • $$6\, \times\, 10^{23}$$
  • $$3\, \times\, 10^{24}$$
  • $$3\, \times\, 10^{27}$$
  • $$6\, \times\, 10^{30}$$
The mean kinetic energy of a gas molecule is proportional to 
  • $$\displaystyle \sqrt { T } $$
  • $$\displaystyle { T }^{ 3 }$$
  • $$\displaystyle T$$
  • None of the above
Which of the following statement is incorrect for gases?
  • Mass of gas cannot be determined by weighing the container in which it is enclosed.
  • Gases do not have a definite shape and volume.
  • The volume of a gas is equal to the volume of the container confining the gas.
  • Confined gas exerts uniform pressure on the walls of its container in all directions.
When the temperature is increased from 0$$^o$$C to 273$$^o$$C, in what ratio the average kinetic energy of molecules changes?
  • 1
  • 5
  • 4
  • 2
The internal energy of a gas:
  • is the sum total of kinetic and potential energies.
  • is the total transitional kinetic energies
  • is the total kinetic energy of randomly moving molecules.
  • is the total kinetic energy of gas molecules
A quantity of air $$(\gamma = 1.4)$$ at 27$$^o$$C is compressed suddenly, the temperature of the air system will
  • fall
  • rise
  • remain unchanged
  • first rise and then fall
The variation of the product of pressure and volume $$PV$$ with volume $$V$$ of a fixed mass of an ideal gas at constant temperature is graphically represented by the curve
Which one of the following represents the correct arrangement in the increasing order of forces of attraction between their particles?
  • Water, air, oxygen
  • Air, sugar, oil
  • Oxygen, water, sugar
  • None of these
Which of the following is the correct increasing order of the force of attraction between their particles?
  • Gold < water < Honey < Air
  • Air< Gold < Water < Honey
  • Air < Water < Honey < Gold
  • Water < Honey < Air < Gold
For a given gas, which of the following relationships is correct at a given temp?
  • $$u_{rms} > u_{av} > u_{mp}$$
  • $$u_{rms} < u_{av} < u_{mp}$$
  • $$u_{rms} > u_{av} < u_{mp}$$
  • $$u_{rms} < u_{av} > u_{mp}$$
The quantity of heat required to heat 1 mole of a monoatomic gas through one degree K at constant pressure is:
  • 3.5 R
  • 2.5 R
  • 1.5 R
  • none of these
The volume of mole of a prefect gas at NTP is ______.
  • 22.4 litres
  • 2.24 litres
  • 100 litres
  • none of these
The volume of a perfect gas at NTP is
  • 22.4 litres
  • 2.24 litres
  • 100 litres
  • None of these
When we cool a gas below its condensation point, the KE of its molecules will 
  • increase
  • decrease
  • remains the same
  • first increase then decrease
When an inflated tyre bursts, the air escaping out __________.
  • will get heated up
  • will be cooled
  • will not undergo any change in its temperature
  • will be liquefied
The temperature to which a gas must be cooled before it can't be liquefied by pressure alone is called its
  • Critical temperature
  • Saturation point
  • Boiling point
  • Freezing point
The molecular kinetic energy of a liquid is:
  • more than molecular kinetic energy of solids
  • more than molecular kinetic energy of gases
  • less than molecular kinetic energy of solids
  • dependent on the matter
When we cool a gas below its condensation point, the K.E. of its molecules:
  • increases
  • decreases
  • remains the same
  • first decreases then increases
Real gases obey ideal gas laws more closely at:
  • low pressure and low temperature
  • low pressure and high temperature
  • high pressure and low temperature
  • high pressure and high temperature
Two gases $$A$$ and $$B$$ having the same temperature $$T$$, same pressure $$P$$ and same volume $$V$$ are mixed. If the mixture is at the same volume $$V$$, the pressure of the mixture is
  • $$P$$
  • $${P}/{2}$$
  • $$2P$$
  • $$4P$$
Which of the following is an assumption of Kinetic theory of matter?
  • Molecules are in a state of continuous motion and possess kinetic energy.
  • The kinetic energy of molecules increases with increase in temperature.
  • The molecules of matter always attract each other due to forces of cohesion and adhesion.
  • All of the above
The gases carbon-monoxide $$(CO)$$ and nitrogen at the same temperature have kinetic energies $${E}_{1}$$ and $${E}_{2}$$ respectively. Then
  • $${E}_{1}=E_2$$
  • $${E}_{1}> {E}_{2}$$
  • $${E}_{1}< {E}_{2}$$
  • $${E}_{1}$$ and $${E}_{2}$$ cannot be compared
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Engineering Physics Quiz Questions and Answers