Compound $X$ is the anhydride of sulphuric acid. The number of $\sigma$-bonds and the number of $\pi$-bonds present in $X$ are,respectively:

What is common between vegetative reproduction and apomixis?

If two angles of $\triangle ABC$ are $45^{\circ}$ and $60^{\circ}$,then the ratio of the smallest side to the greatest side is:

If $Q$ denotes the set of all rational numbers and $f\left(\frac{p}{q}\right)=\sqrt{p^2-q^2}$ for any $\frac{p}{q} \in Q$,then observe the following statements.
$I$. $f\left(\frac{p}{q}\right)$ is real for each $\frac{p}{q} \in Q$
$II$. $f\left(\frac{p}{q}\right)$ is a complex number for each $\frac{p}{q} \in Q$.
Which of the following is correct?

In the circuit shown in the figure,the current $I$ is: (in $\,A$)

The $T.V.$ transmission tower in Delhi has a height of $245 \ m$. The distance up to which the broadcast can be received (taking the radius of earth to be $6.4 \times 10^6 \ m$) is........$km$ :