In an alkaline medium,$H_2O_2$ exists as ........

The decomposition of $H_2O_2$ can be prevented by the addition of which of the following?

$A$ vehicle sounding a whistle of frequency $256 ~Hz$ is moving on a straight road towards a hill with a velocity of $10 ~ms^{-1}$. The number of beats per second observed by a person travelling in the vehicle is (velocity of sound $= 330 ~ms^{-1}$).

These are regarded as major causes of biodiversity loss :
$A.$ Over-exploitation
$B.$ Co-extinction
$C.$ Mutation
$D.$ Habitat loss and fragmentation
$E.$ Migration
Choose the correct option :

The sum of the magnitudes of two forces acting at a point is $16 ~N$. If their resultant is normal to the smaller force and has a magnitude of $8 ~N$,then the forces are:

$\begin{aligned} & \frac{x^2+x+1}{(x-1)(x-2)(x-3)}=\frac{A}{x-1}+\frac{B}{x-2}+\frac{C}{x-3} \\ & \Rightarrow A+C= \end{aligned}$