Question

Uncertainity in position of a $25g$ particle is ${10}^{-5}$. Uncertainity of velocity is: ($h=6.6\times {10}^{-34}Js$)

• A. $1.2\times {10}^{-34}m/s$
• B. $2.1\times {10}^{-28}m/s$
• C. $1.6\times {10}^{-20}m/s$
• D. $1.7\times {10}^{-9}m/s$

Answer 1

The correct option is B $2.1\times {10}^{-28}m/s$

$m=25g=25\times {10}^{-3}Kg,\Delta x={10}^{-5}$

$\Delta x.\Delta v.m>=h/4\pi$

$\Delta v=\frac{6.626\times {10}^{-34}}{25\times {10}^{-3}\times {10}^{-5}\times 4\times 3.14}=2.1\times {10}^{-28}$