How much potential is to be applied to accelerate an electron, so that its de-broglie wavelength should 0.4`Å`?

The potential difference V required for accelerating an electron to have the de-Broglie wavelength of 1 Å is

The potential difference V required for accelerating an electron to have de Broglie wavelength of 1 Å is

Through what potential difference should an electron be accelerated so that its de-Broglie wavelength becomes 0.4Å?

Through what potential difference should an electron be accelerated so that its de-Broglie wavelength becomes 0.4 overset(@)(A) ?

Find the accelerating potential of an electron whose de Broglie wave length is 3 Å

Electron should be accelerated which voltage so that its de-Broglie wavelength will become 0.4 Å.

Through what potential difference should an electron be accelerated so that its de - Broglie wavelenght becomes 0.5 Å