Protein can be most easily removed from which of the following?

If $y=\tan ^{-1}\left(\frac{\sqrt{1+a^2 x^2}-1}{a x}\right)$,then $\left(1+a^2 x^2\right) y^{\prime \prime}+2 a^2 x y^{\prime}$ is equal to

Identify the plant shown in the given figure.

The sensation of fatigue in the muscles after prolonged strenuous physical work is caused by

For the oxidation of $0.2 \ M \ FeSO_4$ solution,$0.965 \ A$ current is passed through it for $1 \ hour$. The volume of the solution that is oxidized in $mL$ is:

$A$ circular disc of radius $R$ is removed from a bigger circular disc of radius $2R$ such that the circumferences of the discs touch. The centre of mass of the new disc is at a distance $\alpha R$ from the centre of the bigger disc. The value of $\alpha$ is