Two thin circular discs $A$ and $B$ of radii $2 \ cm$ and $4 \ cm$ are in a liquid at the same depth. $T_A$ is the thrust on $A$ and $T_B$ is the thrust on $B$. Then $T_A : T_B =$

$20 \ mL$ of gas $A$ and $10 \ mL$ of gas $B$ diffuse through a porous membrane separately in $1 \ minute$. If the vapour density of $B$ is $x$,what is the vapour density of $A$?

The magnitude of surface tension of a liquid depends on the attractive forces between the molecules. Arrange the following in increasing order of surface tension: Water,alcohol $(C_2H_5OH)$,and hexane $(CH_3(CH_2)_4CH_3)$.

If $4 \ g$ of oxygen diffuses through a fine hole,how many grams of hydrogen will diffuse under the same conditions?

$A$ $x : 1$ molar mixture of $He$ and $CH_4$ is contained in a vessel at $20 \ bar$ pressure. Due to a hole in the vessel,the gas mixture leaks out. If the composition of the mixture effusing out initially is $8 : 1$,then the value of $x$ will be

$A$ and $B$ are ideal gases. The molecular weights of $A$ and $B$ are in the ratio of $1: 4$. The pressure of a gas mixture containing equal weights of $A$ and $B$ is $P \text{ atm}$. What is the partial pressure (in $\text{atm}$) of $B$ in the mixture?