What is the correct order of increasing field strength for the ligands $NH_3$,$en$,$CN^-$,and $CO$?

The degeneracy of $d-$orbitals is lost under:
$I$. Strong field ligand
$II$. Weak field ligand
$III$. Mixed field ligand
$IV$. Chelated ligand field
Choose the correct code:

Based on Crystal Field Theory,show the energy level splitting and determine the $d$-electron configuration and magnetic moment for the central metal atom/ion in the following complexes: $[CoF_6]^{3-}$,$[Co(H_2O)_6]^{2+}$,$[Co(CN)_6]^{3-}$.

On what factors does the crystal field splitting in an octahedral complex depend?

If $\Delta_{0} < P$,then what is the electronic arrangement of the metal atom/ion in a complex with $d^4$ configuration?

$\left[ Ti \left( H_{2} O \right)_{6} \right]^{3+}$ absorbs light of wavelength $498 \, nm$ during a $d-d$ transition. The octahedral splitting energy for the above complex is $....... \times 10^{-19} \, J$. (Round off to the Nearest Integer). Given: $h = 6.626 \times 10^{-34} \, Js$,$c = 3 \times 10^{8} \, ms^{-1}$.