  We have observed two dual electromagnetically induced transparency (EIT)
spectra in probe transmission through cold $^{87}Rb$ atoms trapped in a
magneto-optical trap (MOT). These dual EIT peaks are generated in two different
N-systems formed by probe, coupling and control beams interacting with
different levels in $D_{2}$ line transitions of $^{87}Rb$ atom. The dependence
of spectral features of two N-systems on driving beams (\textit{i.e.} coupling
and control beams) strength and detuning has been investigated. The results
show that the dual EIT spectral features in both the N-systems can be
manipulated by varying the strength and detuning of both the driving beams. The
two N-systems have been modelled theoretically using a density matrix formalism
and results have shown a reasonable agreement with the experimental
observations.
