Question

The de Broglie wavelength of a dust particle of mass $1.0\times 10^{- 9} \, kg$ drifting with a speed of $2.2 \, m \, s^{- 1}$ is

• A. $3.0\times 10^{- 25}m$
• B. $1.0\times 10^{- 25} \, m$
• C. $3.0\times 10^{25} \, m$
• D. $1.0\times 10^{25} \, m$

Answer 1

Answer: (A)

Given, Mass of a dust particle, $m=1\times 10^{- 9}kg$ and speed of the dust particle, $v=2.2\,ms^{- 1}$
$\lambda = \frac{\text{h}}{\text{mv}} = \frac{6 \text{.} 6 3 \times 1 0^{- 3 4}}{1 \times 1 0^{- 9} \times 2 \text{.} 2}$
$=3.0\times 10^{- 25}m$ .