If the potential difference used to accelerate electrons is increased four times, by what factor does the de-Broglie wavelength associated with the electrons change?

Question

TestHub · Accepted Answer

The de-Broglie wavelength of an electron accelerated through a potential difference $V$ is given by $λ = \frac{h}{2 m e V}$ .

When the potential difference is increased four times, the new potential difference is $V^{'} = 4 V$ .

The new de-Broglie wavelength is $λ^{'} = \frac{h}{2 m e ( 4 V )} = \frac{1}{2} \frac{h}{2 m e V} = \frac{λ}{2}$ .

Thus, the wavelength is decreased to half.

Answer: Wavelength decreased to half

Physics - Modern Physics Question with Solution | TestHub

Options:

Doubts & Discussion