Identify the operation performed by the circuit given below.

Which of the following sets correctly represents the increasing order of the paramagnetic property of the ions?

Which of the following does not contain any co-ordinate bond?

Anhydrous $Na_2CO_3$ is also known as

$\lim _{x \rightarrow \infty}\left[\sqrt{x^2+2 x-1}-x\right]$ is equal to :

$A$ charged particle with charge $q$ and mass $m$ starts with an initial kinetic energy $K$ at the centre of a uniformly charged spherical region of total charge $Q$ and radius $R$. Charges $q$ and $Q$ have opposite signs. The spherically charged region is not free to move and kinetic energy $K$ is just sufficient for the charged particle to reach the boundary of the spherical charge. How much time does it take the particle to reach the boundary of the region?