"It is impossible to determine simultaneously the exact position and exact momentum of an electron." This statement is called:

The Bohr model of an atom is contradicted by

If the uncertainty in velocity of electron $(\Delta v)$ is $0.1 \ m/s$,the uncertainty in its position $(\Delta x)$ is (given: $m_e = 9.1 \times 10^{-31} \ kg$)

Which of the following statements is correct?

An accelerated electron has a speed of $5 \times 10^{6} \ m \ s^{-1}$ with an uncertainty of $0.02 \ \%$. The uncertainty in finding its location while in motion is $x \times 10^{-9} \ m$. The value of $x$ is $......$ (Nearest integer)
[Use mass of electron $= 9.1 \times 10^{-31} \ kg, h = 6.63 \times 10^{-34} \ J \ s, \pi = 3.14]$

The uncertainties in the velocities of two particles,$A$ and $B$ are $0.05 \ ms^{-1}$ and $0.02 \ ms^{-1}$ respectively. The mass of $B$ is five times that of the mass of $A$. What is the ratio of uncertainties $\frac{\Delta x_A}{\Delta x_B}$ in their positions?