Q136 / 160 · TS EAMCET 2012 · Physics
A proton when accelerated through a potential difference of $V$, has a de-Broglie wavelength $\lambda$ associated with it. If an $\alpha$-particle is to have the same de-Broglie wavelength $\lambda$, it must be accelerated through a potential difference of
- Correct answerA$\frac{V}{8}$
- B$\frac{V}{4}$
- C$4 \mathrm{~V}$
- D$8 \mathrm{~V}$
Solution
$\lambda_p=\lambda_\alpha$
$(m q V)_p=(m q V)_\alpha$
Potential difference
$V_\alpha=\frac{V}{8} \quad\left[\begin{array}{c}\because m_\alpha=4 m_p \\ q_\alpha=2 q_p\end{array}\right]$
Hence, the correct answer is option: 'A'.