Which of the following complex compounds exhibits cis-trans isomerism?

The magnetic moment of the complexes is zero in:

In which of the following orders are the given complex ions arranged correctly with respect to their decreasing spin-only magnetic moment?
$(i)$ $[FeF_{6}]^{3-}$
$(ii)$ $[Co(NH_{3})_{6}]^{3+}$
$(iii)$ $[NiCl_{4}]^{2-}$
$(iv)$ $[Cu(NH_{3})_{4}]^{2+}$

The calculated spin-only magnetic moments of $[Cr(NH_3)_6]^{3+}$ and $[CuF_6]^{3-}$ in $BM$,respectively,are (Atomic numbers of $Cr$ and $Cu$ are $24$ and $29$,respectively).

Which of the following complexes will show geometrical isomerism?

The coordination compound with the molecular formula $[CO(NO_2)(SCN)(en)_2]Br$ exhibits which of the following types of isomerism?