$[Co(NH_3)_4(NO_2)_2]Cl$ exhibits

For $|x| < 1$,the constant term in the expansion of $\frac{1}{(x-1)^2(x-2)}$ is

Bamboo and grasses elongate by the activity of ......

If $y = a \sin x + b \cos x$,then $y^2 + \left( \frac{dy}{dx} \right)^2$ is a

$A$ 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 $= 330 ~ms^{-1}$).

An oil drop having a mass $4.8 \times 10^{-13} ~kg$ and charge $2.4 \times 10^{-18} ~C$ stands still between two charged horizontal plates separated by a distance of $1 ~cm$. If now the polarity of the plates is changed,the instantaneous acceleration of the drop is: $(g = 10 ~ms^{-2})$ (in $~ms^{-2}$)