An electron, accelerated by a potential difference V, has de Brog… - Vidyadip

MCQ

An electron, accelerated by a potential difference $V$, has de Broglie wavelength $\lambda$ . If the electron is accelerated by a potential difference $4V$, its de Broglie wavelength will become $\frac{\lambda }{n}$ where $n=$

✓
$2$
B
$4$
C
$\frac{1}{2}$
D
$\frac{1}{4}$

✓

Answer

Correct option: A.

$2$

a
$\lambda \propto \frac{1}{\sqrt{\mathrm{v}}} \Rightarrow \lambda^{\prime} \propto \frac{1}{\sqrt{\mathrm{v}^{\prime}}}=\frac{1}{\sqrt{4 \mathrm{v}}}$

$\Rightarrow \lambda^{\prime}=\frac{\lambda}{2}=\frac{\lambda}{\mathrm{n}}$

$\Rightarrow \mathrm{n}=2$

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