Physics - Modern Physics Question with Solution | TestHub

$\frac{1}{2}{\text{mv}}^2=\text{qV}$

$\Rightarrow \text{p}=\text{mv}=\sqrt{2\text{mq V}}$

De broglie wavelength,

$\lambda =\frac{\text{h}}{\text{p}}\Rightarrow \frac{{\lambda }_{\alpha }}{{\lambda }_{\text{p}}}=\frac{{\text{P}}_{\text{p}}}{{\text{P}}_{\alpha }}=\sqrt{\frac{{\text{m}}_{\text{p}}{\text{q}}_{\text{p}}}{{\text{m}}_{\alpha }{\text{q}}_{\alpha }}}$

$\Rightarrow \frac{{\lambda }_{\text{p}}}{{\lambda }_{\alpha }}=\sqrt{8}$

The nearest integer is 3

$\therefore$answer is 3