Question

What will be de-Broglie wavelength of an electron moving with a velocity of $3.31\times {10}^5{\text{m s}}^{-1}$?
(Take $h=6.62\times {10}^{-34}\text{J s}$)

• A. $6.6\times {10}^{-9}\text{m}$
• B. $3.1\times {10}^{-37}\text{m}$
• C. $2.2\times {10}^{-9}\text{m}$
• D. $6.0\times {10}^{-7}\text{m}$

Answer 1

The correct option is C $2.2\times {10}^{-9}\text{m}$

de-Broglie wavelength is given by the formula, $\lambda =\frac{h}{p}=\frac{h}{mv}$

$\therefore \lambda =\frac{h}{mv}=\frac{6.62\times {10}^{-34}\text{J s}}{(9.1\times {10}^{-31}\text{kg})\times (3.31\times {10}^5{\text{m s}}^{-1})}$

$\lambda =2.2\times {10}^{-9}\text{m}$