The isobars of one mole of an ideal gas were obtained at three different pressure ( $p_1, p_2$ and $p_3$ ). The slopes of these isobars are $m_1, m_2$ and $m_3$ respectively. If $p_1 < p_2 < p_3$, then the correct relation of the slopes is

The force $(F)$ required to maintain the flow of layers of a liquid is equal to

( $A=$ area of contact of layers

$d z=$ distance between the layers

$d u=$ change in velocity

$\eta=$ coefficient of viscosity)

At 298 K , a flask ' $A$ ' of unknown volume $(V)$ contains oxygen at 5 atm . Another flask ' $B$ ' of volume 2 L contains helium at 3 atm . Two flasks are connected together by a small tube of zero volume. After the two gases are completely mixed, if the resulting mixture is found to have the mole fraction of oxygen as 0.2 , the volume of flask ' $A$ ' (in L ) is

(Assume oxygen and helium as ideal gases)

At $T(\mathrm{~K})$ root mean square (rms) velocity of argon (molar mass $40 \mathrm{~g} \mathrm{~mol}^{-1}$ ) is $20 \mathrm{~ms}^{-1}$. The average kinetic energy of the same gas at $T(\mathrm{~K})$ (in $\mathrm{J} \mathrm{mol}^{-1}$ ) is