Electrons are accelerated from rest through a potential difference V. Their de Broglie wavelength is λ. The accelerating potential difference is increased to 2V. Which of the following gives the new de Broglie wavelength?

A. 2λ

B. \(\sqrt 2 \lambda \)

C. \(\frac{\lambda }{{\sqrt 2 }}\)

D. \(\frac{\lambda }{2}\)

C