Question

What will be the kinetic energy of an electron having de-Broglie wavelength $2\stackrel{o}{A}$ ?

• A. 37.5 eV
• B. 75 eV
• C. 150 eV
• D. 30 eV

Answer 1

Answer: (A)

$\lambda =\frac{12.27}{\sqrt{V}}$
$V=\frac{{(12.27)}^2}{{\lambda }^2}=\frac{150}{{\lambda }^2}$
$E=VeV=37.5eV$