Limestone is present in the blast furnace production of iron in order to:
$(I)$ provide a source of $CaO$
$(II)$ remove some impurities
$(III)$ supply $CO_2$

In which of the following compounds is the transition metal in oxidation state zero?

If $\int \frac{d \theta}{\cos ^{2} \theta(\tan 2 \theta+\sec 2 \theta)}=\lambda \tan \theta+2 \log _{e}|f(\theta)|+C$ where $C$ is a constant of integration,then the ordered pair $(\lambda, f(\theta))$ is equal to

The solution set of $|x-1|+|x-2| < 3$ is...

Two long conductors,separated by a distance $d$,carry currents $I_1$ and $I_2$ in the same directions. They exert a force $F$ on each other. Now,the current in one of them is increased to two times its original value and its direction is reversed. The distance is also increased to $3d$. The new value of the force between them is:

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. Tranquilizers	$I$. Anti blood clotting
$B$. Aspirin	$II$. Salvarsan
$C$. Antibiotic	$III$. Antidepressant drugs
$D$. Antiseptic	$IV$. Soframicine

Choose the correct answer from the options given below: