Which one of the following compounds does not decolourise an acidified aqueous solution of $KMnO_4$?

Which one of the following orders is correct for the bond dissociation energies of halogen molecules?

Identify the figure shown in the transverse section ($T$.$S$.):

The solution of $\cos y + (x \sin y - 1) \frac{dy}{dx} = 0$ is

$A$ circular disc of radius $R$ and thickness $\frac{R}{6}$ has moment of inertia $I$ about an axis passing through its centre and perpendicular to its plane. It is melted and recasted into a solid sphere. The moment of inertia of the sphere about its diameter as axis of rotation is

If a polygon of $n$ sides has $275$ diagonals,then $n$ is equal to