The gas used in the hydrogenation of vegetable oils in the presence of nickel as catalyst is

An inductor of $2\,H$ and a resistance of $10\,\Omega$ are connected in series with a battery of $5\,V$. The initial rate of change of current is.....$A/s$.

What is the bond angle in $ClO_2$ (OClO) (in $^{\circ}$)?

The magnetic susceptibility of a paramagnetic material at $-73\,^{\circ}C$ is $0.0075$. What will be its value at $-173\,^{\circ}C$?

Match the common name given in column $I$ with their taxonomic category family given in column $II$ and choose the correct combination from the options given below.

Column-$I$ (Common Name)	Column-$II$ (Taxonomic category- Family)
$A$. Man	$I$. Poaceae
$B$. Datura	$II$. Anacardiaceae
$C$. Mango	$III$. Solanaceae
$D$. Wheat	$IV$. Hominidae

Let $PQ$ and $RS$ be tangents at the extremities of the diameter $PR$ of a circle of radius $r$. If $PS$ and $RQ$ intersect at a point $X$ on the circumference of the circle,then $2r$ equals