An electron is accelerated through a potential difference of V volt. It has a wavelength λ associated with it…..

Q. An electron is accelerated through a potential difference of V volt. It has a wavelength λ associated with it. Through what potential difference an electron must be accelerated so that its de Broglie wavelength is the same as that of a proton? Take mass of proton to be 1837 times larger than the mass of electron.

(a) V volt

(b) 1837V volt

(c) V/1837 volt

(d) √(1837)volt

Ans: (d)

Sol: λ = h/√(2meV)

λ’ = h/√(2m’eV’)

Since , λ = λ’

h/√(2meV) = h/√(2m’eV’)

m V =m’V’

m V = m×1837×V’

V’ = V/1837 volt