Question

Uncertainty in the position of an electron (mass = 9.1x$10^{-31},$ kg) moving with a velocity 300 $ms^{-1}$, accurate upon 0.001% will be :
$\left(h=6.63\times10^{-34} JS\right)$

• A. $19.2 \times10^{-2} m$
• B. $5.76\times10^{-2} m$
• C. $1.92\times10^{-2} m$
• D. $3.84\times10^{-2} m$

Answer 1

Answer: (C)

$\Delta x \cdot\Delta v \ge \, \frac{h}{4\pi m}$
$\Delta x =\frac{6.63\times10^{-34}}{4\times3.14\times9.1\times10 ^{-31}\times300\times0.001\times10^{-2}}$
$0.01933$
$=1.93\times10^{-2}$