What is the role of limestone during the extraction of iron from haematite ore?

$A$ body thrown vertically upwards from the ground reaches a maximum height $h$. The ratio of the kinetic and potential energies of the body at a height $40 \%$ of $h$ from the ground is

The position vector of a point lying on the line joining the points whose position vectors are $\hat{i}+\hat{j}-\hat{k}$ and $\hat{i}-\hat{j}+\hat{k}$ is:

The binding energy per nucleon of $^{16}O$ is $7.97 \, MeV$ and that of $^{17}O$ is $7.75 \, MeV$. The energy (in $MeV$) required to remove a neutron from $^{17}O$ is:

If $z = \sec(y - ax) + \tan(y + ax)$,then $\frac{\partial^2 z}{\partial x^2} - a^2 \frac{\partial^2 z}{\partial y^2} = $

The correct order of energies of $d-$ orbitals of a metal ion in a square planar complex is: