The uncertainty in the position of an electron `(mass = 9.1 xx 10^-28 g)` moving with a velocity of `3.0 xx 10^4 cm s^-1` accurate up to `0.001 %` will be
(Use `(h)/(4 pi)` in the uncertainty expression, where `h = 6.626 xx 10^-27 erg - s`)

Options

A. `1.93` cm
B. `3.84` cm
C. `5.76` cm
D. `7.68` cm

Answer

A

Explanation

Given mass of an electron (m) ` = 9.1 xx 10^(-28) g`
Velocity of electron (v) ` =3 xx10^(4) cm//s`:
Accuray in velocity =` 0.001% = (0.001)/(100)`
Actual velocity of the electron
`(Delta V) = 3 xx 10^(4) xx (0.001)/(100) = 0.3 cm//s`