Question

An electron is accelerated through a potential difference of 10000 volt its de broglie wavelength is

Answer 1

potential difference , V = 10000 volts

charge on electron , q = 1.6 × 10^-19 C

mass of electron, m = 9.1 × 10^-31 Kg

a/c to De-broglie's wavelength,

\lambda=\frac{h}{\sqrt{2qVm}}λ=

2qVmh

where h is plank's constant. i.e., h = 6.64 × 10^-34 Js

so, wavelength = 6.64 × 10^-34/√(2 × 1.6 × 10^-19 × 10000 × 9.1 × 10^-31)

= 6.64 × 10^-34/(5.4 × 10^-23) m

= (6.64/5.4) × 10^(-34 + 23) m

= 1.2296 × 10^-11 m

= 12.296 × 10^-12 m or 12.296 pm

hence, De-broglie's wavelength is 12.296 pm