Question

The ratio of de Broglie wavelengths of a proton and a neutron moving with the same velocity is nearly

• A. 1
• B. $\sqrt{2}$
• C. $\frac{1}{\sqrt{2}}$
• D. None of these

Answer 1

The correct option is A 1

Since, de Broglie wavelength, $\lambda =\frac{h}{mV}$
$\therefore \frac{{\lambda }_P}{{\lambda }_N}=\frac{\left(\frac{h}{m_P{V}_P}\right)}{\left(\frac{h}{m_N{V}_N}\right)}=\frac{m_N}{m_P}\times \frac{V_N}{V_P}=1$
(Since, $m_N\simeq m_P)$
$(\&V_P=V_N)$