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CUET · PHYSICS · PYQ PAPER 2025

A proton has double the kinetic energy of an \( \alpha \)- particle. The ratio of the de-Broglie wavelength of the proton to that of \( \alpha \)- particle will be

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

Answer & Solution

Correct Answer

(C) \(\frac{\sqrt{2}}{1}\)

Step-by-step Solution

Detailed explanation

\( \lambda = \frac{h}{\sqrt{2mK}} \) \( \frac{\lambda_p}{\lambda_\alpha} = \sqrt{\frac{m_\alpha K_\alpha}{m_p K_p}} \) \( \frac{\lambda_p}{\lambda_\alpha} = \sqrt{\frac{(4m_p) K_\alpha}{m_p (2K_\alpha)}} \) \( \frac{\lambda_p}{\lambda_\alpha} = \sqrt{\frac{4}{2}} = \sqrt{2} \)