Which of the following compounds will react with $NaHCO_3$ solution to give sodium salt and carbon dioxide?

The ratio between kinetic and potential energies of a body executing simple harmonic motion,when it is at a distance of $\frac{1}{N}$ of its amplitude from the mean position is

$A$ current of $2\, A$ flows in a system of conductors as shown. The potential difference $(V_A - V_B)$ will be ................ $V$.

The compressibility factor for an ideal gas is

The locus of the midpoints of the chords of the parabola $y^2 = 4ax$ which pass through the origin is:

In which of the following ionization processes does the bond energy increase and the magnetic behaviour change from paramagnetic to diamagnetic?