Question

The measurement of the electron position is associated with an uncertainty in momentum, which is equal to $1\times {10}^{-18}$ $g$ $cm$ $s^{-1}$.

The uncertainty in electron velocity is: (mass of an electron is $9\times {10}^{-28}g$)

• A. $1\times {10}^5$ $cm$ $s^{-1}$
• B. $1\times {10}^{11}$ $cm$ $s^{-1}$
• C. $1\times {10}^9$ $cm$ $s^{-1}$
• D. $1\times {10}^6$ $cm$ $s^{-1}$

Answer 1

The correct option is C $1\times {10}^9$ $cm$ $s^{-1}$

The uncertainity in the momentum $\Delta P=1\times {10}^{-18}gcm{s}^{-1}$
Mass of electron $m=9\times {10}^{-28}g$
The uncertainity in the velocity $\Delta V=\frac{\Delta P}{m}$
The uncertainity in the velocity $\Delta V=\frac{1\times {10}^{-18}gcm{s}^{-1}}{9\times {10}^{-28}g}$
The uncertainity in the velocity$\Delta V=1\times {10}^{9}cm{s}^{-1}$

Thus, the correct option is $C$