11th Standard Physics Kinetic Theory of Gases English Medium Free Online Test One Mark Questions with Answer Key 2020 - 2021

1.

The average energy of a molecules of a mono atomic gas at temperature T is _____________ (K = Boltzmann constant).

(a)

\(\frac{1}{2}\)kT

(b)

kT

(c)

\(\frac{3}{2}\)kT

(d)

\(\frac{5}{2}\)kT

2.

A cylinder of capacity 20 litres is filled with hydrogen gas. The total average K.E. of translatory motion of its molecules is 1.5\(\times\)10⁵ J. The pressure of hydrogen in the cylinder is ________.

(a)

2\(\times\)10⁶Nm^-2

(b)

3\(\times\)10⁶Nm^-2

(c)

4\(\times\)10⁶Nm^-2

(d)

5\(\times\)10⁶Nm^-2

3.

The kinetic theory of gases breaks down most at _________.

(a)

low pressure and high temperature

(b)

high pressure and low temperature

(c)

low pressure and low temperature

(d)

high pressure and high temperature

4.

The pressure exerted on the walls of the container by a gas is due to the fact that the gas molecules _________.

(a)

lose their K.E

(b)

Stick to the walls

(c)

are accelerated towards the walls

(d)

change their momenta due to collision with the walls.

5.

The mean translational K.E. of a perfect gas molecule at absolute temperature T is _____________ (K is Boltzmann constant)

(a)

\(\frac{1}{2}\)kT

(b)

kT

(c)

\(\frac{3}{2}\)kT

(d)

\(\frac{5}{2}\)kT

6.

Two vessels have equal volumes. One of them contains hydrogen at one atmosphere and the other helium at two atmospheres. If both the samples are at the same temperature, the rms velocity of the hydrogen molecules is _________.

(a)

equal to that of the helium molecules

(b)

twice that of the helium molecules

(c)

half that of the helium molecules

(d)

\(\sqrt 2\) times that of the helium molecules

7.

If the absolute temperature of a gas is increased 3 times the rms velocity of the molecules will be _________.

(a)

3 times

(b)

9 times

(c)

\(\sqrt 3\) times

(d)

\(\sqrt 6\) times

8.

The temperature of an ideal gas is increased from 27°C to 927°C. The root mean square speed of its molecules becomes ________________.

(a)

3 times

(b)

double

(c)

4 times

(d)

6 times

9.

According to the kinetic theory of gases ____________.

(a)

the pressure of a gas is proportional to the rms speed of the molecules

(b)

the rms speed of the molecules of a gas is proportional to the absolute temperature

(c)

the rms speed of the molecules of a gas is proportional to the square root of the absolute temperature

(d)

the pressure of a gas is proportional to the square root of the rms speed of the molecules

10.

The slope at any point on the curve in PV graph for a gas is gn involving the reaction _______________.

(a)

\(\frac { dp }{ p } =\frac { dV }{ V } \)

(b)

\(\frac { dp }{ V } =-\frac { dV }{ P } \)

(c)

\(\frac { dp }{ p } =\frac { dV }{ V } \)

(d)

\(\frac { dp }{ V } =\frac { dV }{ P } \)

11.

In an adiabatic change, the pressure and temperature of a mono - atomic gas are related as p\(\times\)TC, where C equals ____________.

(a)

\(\frac{2}{5}\)

(b)

\(\frac{5}{2}\)

(c)

\(\frac{3}{5}\)

(d)

\(\frac{5}{3}\)

12.

The gas having average speed four times as that of SO₂ (molecule mass 64) is ____________.

(a)

He (molecule mass 64)

(b)

O₂ (molecule mass 4)

(c)

M₂ (molecule mass 32)

(d)

CH₄(molecule mass 16)

13.

The average K.E of a molecule __________.

(a)

is inversely proportional to the molecular mass of the gas.

(b)

is inversely proportional to the absolute temperature mass of the gas.

(c)

is directly proportional to the absolute temperature mass of the gas.

(d)

is not dependent on absolute temperature of the gas.

14.

According to Dalton's law of partial pressures ______________

(a)

total pressure of a mixture of real gases is the sum of factored in - virtual pressure

(b)

total pressure of a mixture of ideal gases is the difference partial pressure

(c)

total pressure of a mixture of real gases is the sum of pressures

(d)

total pressure of a mixture of real gases is the sum of partial pressure

15.

Kinetic theory ___________.

(a)

Correctly explains specific heat capacities of many liquid

(b)

Correctly explains specific heat capacities of many gases

(c)

Correctly explains specific heat capacities of many solids

(d)

Correctly explains specific heat capacities of many super cooled liquid

16.

For a given gas molecule at a fixed temperature, the area under the Maxwell-Boltzmann distribution curve is equal to

(a)

\(\frac{PV}{KT}\)

(b)

\(\frac{KT}{PV}\)

(c)

\(\frac{P}{NKT}\)

(d)

PV

17.

If s_P and s_V denote the specific heats of nitrogen gas per unit mass at constant pressure and constant volume respectively, then

(a)

s_P - s_V = 28R

(b)

s_P - s_V = R/28

(c)

s_P - s_V = R/14

(d)

s_P - s_V = R

18.

A container has one mole of monoatomic ideal gas. Each molecule has f degrees of freedom. What is the ratio of \(\gamma =\frac { { C }_{ p } }{ { C }_{ V } } \)

(a)

f

(b)

\(\frac{f}{2}\)

(c)

\(\frac{f}{f+2}\)

(d)

\(\frac{f+2}{f}\)

19.

The average translational kinetic energy of gas molecules depends on

(a)

number of moles and T

(b)

only on T

(c)

P and T

(d)

P only

20.

An ideal gas is maintained at constant pressure. If the temperature of an ideal gas increases from 100K to 1000K then the rms speed of the gas molecules

(a)

increases by 5 times

(b)

increases by 10 times

(c)

remains same

(d)

increases by 7 times