The types of hybrid orbitals of nitrogen in ${{\mathrm{NO}}_{2 }}^{+}$,${{\mathrm{NO}}^{-}}_3$ and. ${{\mathrm{NH}}^{+}}_4$ respectively are expected to be:

Each molecule's hybridization provides an understanding of the hybrid orbitals.

${\mathrm{NO}}_2^{+}$is sp hybridised 

${\mathrm{NO}}_3^{-}$ is ${\mathrm{sp}}^2$ hybridised

${\mathrm{NH}}_4^{+}$is ${\mathrm{sp}}^3$ hybridised