If the potential difference used to accelerate electrons is doubled, by what factor does the de-Broglie…
If the potential difference used to accelerate electrons is doubled, by what factor does the de-Broglie wavelength associated with the electrons change?
Wavelength is increased to $\sqrt{2}$ times.
Wavelength is decreased to $\sqrt{2}$ times.
Wavelength is decreased to $\frac{1}{\sqrt{2}}$ times.
Wavelength is increased to $\frac{1}{\sqrt{2}}$ times.
Solution
De Broglie wavelength,
$\lambda=\frac{h}{\sqrt{2 m q V}} \propto \frac{1}{\sqrt{V}}$
If the potential difference $V$ is doubled, the de Broglie wavelength is decreased to $\frac{1}{\sqrt{2}}$ times.
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