Question

The measurement of the electron position is associated with
an uncertainty in momentum, which is equal to 1×10⁻¹⁸ g cm s⁻¹.
The uncertainty in electron velocity is, (mass of an electron is
9 × 10⁻²⁸ g)
(a) 1 × 10⁹ cm s⁻¹ (b) 1 × 10⁶ cm s⁻¹
(c) 1 × 10⁵ cm s⁻¹ (d) 1 × 10¹¹ cm s⁻¹

Answer 1

Answer:

a, the uncertainty in electron velocity

Answer 2

The uncertainty in electron velocity is, (mass of an electron is:

• It is given by Heisenberg's Uncertainty principle, which states that " The more precisely the position of some particle is determined, the less precisely its momentum can be predicted from initial conditions, and vice versa."

• ∆x.∆P ⩾ h/4π

where h = Planck's constant

• We are given ∆P = 1×10⁻¹⁸ g cm s⁻¹

mass = 9 × 10⁻²⁸ g

• We know that, P = mv

• So, ∆P = m∆v

∆v = ∆P/m

=1×10⁻¹⁸ g cm s⁻¹/ 9 × 10⁻²⁸ g

= 1 × 10⁹ cm s⁻¹

Hence, option a is correct.