A proton of mass $m$ and charge $e$ is projected from a very large distance towards an $\alpha$-particle with velocity $v$. Initially $\alpha$-particle is at rest, but it is free to move. If gravity is neglected, then the minimum separation along the straight line of their motion will be
A proton of mass $m$ and charge $e$ is projected from a very large distance towards an $\alpha$-particle with velocity $v$. Initially $\alpha$-particle is at rest, but it is free to move. If gravity is neglected, then the minimum separation along the straight line of their motion will be
- [KVPY 2018]
- A
$e^2 / 4 \pi \varepsilon_0 m v^2$
- B
$5 e^2 / 4 \pi \varepsilon_0 m v^2$
- C
$2 e^2 / 4 \pi \varepsilon_0 m v^2$
- D
$4 e^2 / 4 \pi \varepsilon_0 m v^2$
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- [JEE MAIN 2019]
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- [AIIMS 2003]
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