Physics

Problem

An electron is first accelerated from rest through a potential difference of

100\,\text{V}

, acquiring a de Broglie wavelength

\lambda_1

. It is then accelerated through an additional potential

V_2

in the same direction so that its new wavelength becomes

\lambda_2 = \dfrac{\lambda_1}{3}

. The value of

V_2

is a)

200\,\text{V}

800\,\text{V}

900\,\text{V}

300\,\text{V}