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MHT CET · Physics · Magnetic Effects of Current

The ratio of momenta of an electron and an \(\alpha\) -particle which are accelerated from rest by a potential difference of \(100 \mathrm{~V}\) is

  1. A 1
  2. B \(\sqrt{\frac{2 m_{e}}{m_{\alpha}}}\)
  3. C \(\sqrt{\frac{m_{e}}{m_{\alpha}}}\)
  4. D \(\sqrt{\frac{m_{e}}{2 m_{\alpha}}}\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\sqrt{\frac{m_{e}}{2 m_{\alpha}}}\)

Step-by-step Solution

Detailed explanation

Momentum \(p=m v\) and \(v=\sqrt{\frac{2 q V}{m}}\)
\(
\begin{array}{c}
p=\sqrt{2 q m V} \\
p=\sqrt{q m} \\
\frac{p_{e}}{p_{\alpha}}=\sqrt{\frac{e m_{e}}{2 e m_{\alpha}}}
\end{array}
\)
\(\frac{p_{e}}{p_{\alpha}}=\sqrt{\frac{m_{e}}{2 m_{\alpha}}}\)