Name the chronic respiratory disorder caused mainly by cigarette smoking.

$A$ body of mass $5 \ kg$ makes an elastic collision with another body at rest and continues to move in the original direction after the collision with a velocity equal to $\frac{1}{10}$th of its original velocity. Then the mass of the second body is (in $kg$)

$A$ random variable $X$ takes the values $0, 1$ and $2$. If $P(X=1)=P(X=2)$ and $P(X=0)=0.4$,then the mean of the random variable $X$ is

Identify the product in the following reaction:
$Phenol + CHCl_3 + NaOH \rightarrow \text{Product}$

$Na^+$,$Mg^{2+}$,$Al^{3+}$,and $Si^{4+}$ are isoelectronic. What is the order of their ionic radii?

$A$ rocket with a lift-off mass $2 \times 10^4 \ kg$ is blasted upwards with an initial acceleration of $5 \ m \ s^{-2}$. The initial thrust of the blast is (Take $g = 10 \ m \ s^{-2}$)