What is $Endosulfan$?

In the figure $(a)$,half of the meter scale is made of wood while the other half is made of steel. The wooden part is pivoted at $O$. $A$ force $F$ is applied at the end of the steel part. In figure $(b)$,the steel part is pivoted at $O'$ and the same force is applied at the wooden end (in a horizontal plane).

$A$ current of $5 ~A$ is flowing at $220 ~V$ in the primary coil of a transformer. If the voltage produced in the secondary coil is $2200 ~V$ and $50 \%$ of power is lost,then the current in the secondary coil will be: (in $~A$)

If $y=\sin (\log _e x)$,then $x^2 \frac{d^2 y}{d x^2}+x \frac{d y}{d x}$ is equal to

$\sinh^{-1}\left(\frac{x}{\sqrt{1-x^2}}\right)$ is equal to

The Lanthanoid contraction is responsible for the fact that