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Question: Answered & Verified by Expert
If the potential difference used to accelerate electrons is doubled, by what factor does the de-Broglie wavelength associated with electrons change?
PhysicsDual Nature of MatterMHT CETMHT CET 2023 (10 May Shift 2)
Options:
  • A Wavelength in increased to $\frac{1}{\sqrt{2}}$ times.
  • B Wavelength in increased to $\frac{1}{2}$ times.
  • C Wavelength in decreased to $\frac{1}{\sqrt{2}}$ times.
  • D Wavelength in decreased to $\frac{1}{2}$ times.
Solution:
1244 Upvotes Verified Answer
The correct answer is: Wavelength in decreased to $\frac{1}{\sqrt{2}}$ times.
From $\lambda=\frac{\mathrm{h}}{\sqrt{2 \mathrm{mqV}}}$,
$\lambda \propto \frac{1}{\sqrt{V}}$
If potential difference is doubled, $\lambda \propto \frac{1}{\sqrt{2 \mathrm{~V}}}$
$\therefore \quad \lambda$ is decreased by $\frac{1}{\sqrt{2}}$ times.

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