$A$ solution of urea (molar mass $60 \ g \ mol^{-1}$) boils at $100.18 \ ^oC$ at atmospheric pressure. If $K_f$ and $K_b$ for water are $1.86$ and $0.512 \ K \ kg \ mol^{-1}$ respectively,the above solution will freeze at ......... $^oC$.

$A$ ball of mass $m$ and radius $r$ is gently released in a viscous liquid. The mass of the liquid displaced by it is $m'$ such that $m > m'$. The terminal velocity is proportional to

$A$ bullet is fired from a gun. The force on the bullet is given by $F = 600 - 2 \times 10^5 t$,where $F$ is in newton and $t$ is in second. The force on the bullet becomes zero as soon as it leaves the barrel. What is the impulse imparted to the bullet (in $N-s$)?

$A$ galvanometer,having a resistance of $50 \,\Omega$,gives a full-scale deflection for a current of $0.05 \,A$. The length in meters of a resistance wire of cross-sectional area $2.97 \times 10^{-2} \,cm^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of $5 \,A$ current is (Specific resistance of the wire = $5 \times 10^{-7} \,\Omega \cdot m$)

How many unit cells are present in $39 \ g$ of potassium that crystallises in body-centred cubic structure? [At. wt. of $K = 39$]

Vegetative propagation in Pistia occurs by: