26105.One mole of mono atomic gas (γ = 5/3) is mixed with one mole of diatomic gas (γ = 7/5) what will be the value of γ for the mixture?
1.5
2.5
1.0
2
26106.The r.m.s velocity of the molecules of an ideal gas is C at a temperature of 100 K. at what temperature is r.m.s. velocity will be doubled?
200 K
400 K
300 K
50 K
26107.The r.m.s. speed of the molecules of an enclosed gas is $x$. what will be the r.m.s. speed, if the pressure of the gas is doubled but the temperature is kept constant?
$x$
$\dfrac{x}{2}$
2$x$
$\sqrt{x}$
26108.The r.m.s. velocity of the molecules in the sample of helium is 5/7th that of the molecules in the sample of hydrogen. If the temperature of the hydrogen sample is 0°C that of helium is
0°C
0 K
273°C
100°C
26109.K.E. per unit volume is given by
E = $\dfrac{3}{2}P$
E = $\dfrac{2}{3}P$
E = $\dfrac{1}{2}mv^2$
None of these
26110.A gas is taken in a sealed container at 300 K. it is heated at constant volume to a temperature 600 K. the mean K.E. of its molecules is
Halved
Doubled
Tripled
Quadrupled
26111.If for a gas $\left(\dfrac{R}{C_V}\right)$ = 0.67 this gas is made up of molecules which are
Diatomic
Mixture of diatomic and polyatomic
Mono atomic
Polyatomic
26112.R.m.s. velocity of a gas molecule of mass m at given temperature is proportional to
m0
m
$\sqrt{m}$
$\dfrac{1}{\sqrt{m}}$
26113.The specific heat of a substance at its boiling point or melting point
Is zero
Is infinity
Is negative
Lies between 0 and 1
26114.A wall is hit elastically and normally by n balls per second, all the balls have the same mass m and are moving with the same velocity u. the force exerted by the balls on the wall is
mnu2
2 mnu2
2 mnu
$\dfrac{1}{2}$ mnu2
26115.CP and CV are the principal specific heat of a gas. In terms of mechanical units, CP – CV is equal to
R
$\dfrac{R}{J}$
$\dfrac{R}{MJ}$
$\dfrac{R}{M}$
26116.A sample of an ideal gas occupies a volume V at a pressure P and absolute temperature T, the mass of each molecules is m. the expression for the density of gas is (k = Boltzmann constant)
mkT
$\dfrac{P}{kT}$
$\dfrac{P}{kTV}$
$\dfrac{Pm}{kT}$
26117.The r.m.s velocity of hydrogen gas molecules at N.T.P. is v m/se. the gas is heated at constant volume till the pressure becomes 4 times. The final r.m.s. velocity is
v/2
v
2v
4v
26118.The average translational K.E. of O2 molecules (Molecular weight =32) at a particular temperature is .035 eV. What is the average translational K.E. of N2 Molecules (Molecular weight = 28) at the same temperature?
0.028 eV
0.055 eV
0.035 eV
0.075 eV
26119.The frequency of a light wave in a material is 3 × 1014 Hz and the wavelength is 6000 Å. What is the refractive index of the material?
$\dfrac{3}{2}$
$\dfrac{4}{3}$
$\dfrac{5}{3}$
$\dfrac{3}{5}$
26120.If two gases of molecular weights M1 and M2 are at same pressure and temperature, ratio of their r.m.s. speed will be
M2: M1
M1: M2
$\sqrt{M_1} : \sqrt{M_2}$
$\sqrt{M_2} : \sqrt{M_1}$
26121.Which one of the following quantities can be zero on a average for the molecules of an ideal gas in equilibrium?
Kinetic energy
Density
Momentum
Speed
26122.Moon has no atmosphere because
It is far away form the surface of the earth
Its surface temperature is 10°C
The r.m.s. velocity of all the gas molecules is more then the escape velocity of the moon’s surface
The escape velocity of the moon’s surface is more than the r.m.s velocity of all molecules
26123.At a certain temperature, hydrogen molecules have r.m.s. velocity of 3 km/s. what is the r.m.s velocity of the oxygen molecules at the same temperature?
0.25 km/s
0.5 km/s
0.75 km/s
6 km/s
26124.We have a jar ‘A’ filled with a gas characterized by parameter P, V and T. another jar ‘B’ filled with a gas with parameters 2P, $\dfrac{V}{2}$ and 2T, where symbols have their usual meanings. The ratio of the number of molecules of jar ‘A’ to those of jar ‘B’ is
1: 1
1: 2
2: 1
4: 1