\(\frac{{\lambda p}}{{{\lambda _\alpha }}}\,\, = \,\,\frac{h}{{\sqrt {2{m_p}{q_p}V} }}\,\, \times \,\,\frac{{\sqrt {2{m_\alpha }{q_\alpha }V} }}{h}\)

\( = \,\,\sqrt {\frac{{{m_\alpha }}}{{{m_p}}}\,.\,\,\frac{{{q_\alpha }}}{{{q_p}}}} \,\,\,\sqrt {\frac{{4m}}{m}\,\,.\,\frac{{2e}}{e}}  = \,\,2\sqrt 2 \)