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

Options

A. 999 V
B. 242 V
C. 941 V
D. 520 V

Answer

C

Explanation

`lambda =12.27/sqrt(V)`
`lambda^(2)=(12.27xx12.27)/V`
`V=(12.27xx12.27)/0.16=914 V`.