Which concentrations can be calculated if the mole fraction and density of an aqueous solution of $HCl$ are known?
$1.$ Molality $\ \ 2.$ Molarity $\ \ 3.$ $\%(w/w)$

$A$ circular disc is rolling on a horizontal plane. Its total kinetic energy is $300\,J$. What is its translational kinetic energy in $J$?

Suppose $X$ follows a binomial distribution with parameters $n$ and $p$, where $0 < p < 1$. If $\frac{P(X=r)}{P(X=n-r)}$ is independent of $n$ for every $r$, then $p$ is equal to

When $100\,V$ $DC$ is applied across a solenoid,a current of $1\,A$ flows in it. When $100\,V$ $AC$ is applied across the same coil,the current drops to $0.5\,A$. If the frequency of the $AC$ source is $50\,Hz$,the impedance and inductance of the solenoid are:

Which complex is most stable?
Where $k_d = \text{Dissociation constant}$

If in a $\triangle ABC$,$r_3 = r_1 + r_2 + r$,then $\angle A + \angle B$ is equal to (in $^{\circ}$)