Question

Calculate the wavelength associated with an electron moving with a velocity of $10^{6} m / s$ (mass of $e^{-}=9.1 \times 10^{-31} kg,\, \left. h=6.6 \times 10^{-34} kg\, m ^{2} s ^{-1}\right)$

• A. $ 6.2\times 10^{-8}\,m $
• B. $ 7.25\times 10^{-8}\,m $
• C. $ 6.25\, \mathring{A}$
• D. None of the above

Answer 1

Answer: (D)

According to de-Broglie equation
$\lambda=\frac{h}{m v}$
$=\frac{6.6 \times 10^{-34} kg m ^{2} s ^{-1}}{9.1 \times 10^{-31} kg \times 10^{6} ms ^{-1}}$
$=0.725 \times 10^{-9} m$
$=7.25 \times 10^{-10} m$