$\begin{array}{1 1} \text{when the electrons jump from}\; n_3 = 4 level \;to n_2=3 \;level \\ \text{when the electrons jump from} \;n_4 = 5\; level \;to n_3=4 \;level \\ \text{when the electrons jump from} \;n_2 = 3\; level \;to n_1=2 \;level \\\text{when the electrons jump from higher to ground level } \end{array} $