absorbed wave length order of \(\lambda \) \(Red > Green > Blue\) \(L_3 > L_1 > L_2\)
\(\therefore \) Strength of ligand \(\alpha \,\,\Delta \,\,\alpha \,\,1/\lambda\)
\(\therefore \) Strength of ligand \(L_2 > L_1 > L_3\)
$\operatorname{cis}-\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-},\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$
$\operatorname{cis}-\left[\mathrm{Pt}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{2+}, \text { cis }-\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}$
$\text {trans }-\left[\mathrm{Pt}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{2+}, \text { trans }-\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-}$