\(\therefore \,\,E\,\, = \,\,\frac{{hc}}{\lambda }\)
હવે, \(\frac{{hE}}{3}\,\, - \,\,E\,\, = \,\,\frac{{hc}}{{\lambda '}}\,\,\,\)
\(\therefore \,\,\,\frac{E}{3}\,\, = \,\,\frac{{hc}}{{\lambda '}}\)
\(\frac{1}{3}\,\,\left( {\frac{{hc}}{\lambda }} \right)\,\, = \,\,\frac{{hc}}{{\lambda '}}\,\,\,\)
\(\therefore \,\,\lambda '\,\, = \,\,3\,\lambda \)
(હાઈડ્રોજન પરમાણુની ત્રિજ્યા $= 0.51\,\mathring A$,લો)