Concept:An accelerating voltage imparts electrical potential energy into an electron, converting it completely into kinetic energy, which in turn defines its momentum and wavelength.
Formula:$$ K.E = eV $$
$$ \lambda = \frac{h}{\sqrt{2m(eV)}} $$
Solution:- The formula explicitly places the voltage \( V \) inside the denominator.
- This establishes an inverse-square-root relationship between the associated matter wavelength and the applied voltage.
- Therefore, if you actively decrease the voltage \( V \), the denominator shrinks, causing the resulting wavelength \( \lambda \) to increase.
Why other options are incorrect:Decreasing the voltage removes kinetic energy, making the electron slower. A slower electron has less momentum, leading to a larger, not smaller, wavelength.
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