Q105 / 180 · AIIMS 2018 (27 May) · Physics
A deutron has an energy of $4 \mathrm{MeV}$ when accelerated through a potential difference $V$. What will be the energy of an $\alpha$-particle accelerated by source $V$ ?
- A$4 \mathrm{MeV}$
- Correct answerB$8 \mathrm{MeV}$
- C$12 \mathrm{MeV}$
- D$20 \mathrm{MeV}$
Solution
Energy of a charged particle when accelerated through V
$\begin{gathered}E=q V \\ \text { So, } \quad \frac{E_d}{E_\alpha}=\frac{q_d}{q_\alpha} \times \frac{V_d}{V_\alpha}=\frac{(e) V}{(2 e) V}=\frac{1}{2} \\ E_\alpha=2 E_d=2 \times 4 \mathrm{MeV}=8 \mathrm{MeV}\end{gathered}$
Hence, the correct answer is option: 'B'.