If the uncertainty in velocity is $\frac{1}{2m} \sqrt{\frac{h}{\pi}}$, then the ratio of uncertainty in position and momentum is (in $: 1$)

What parameters are required to determine the position of an electron? Explain.

Given below are two statements:
Statement $I:$ According to Bohr's model of hydrogen atom,the angular momentum of an electron in a given stationary state is quantised.
Statement $II:$ The concept of electron in Bohr's orbit,violates the Heisenberg uncertainty principle.
In the light of the above statements,choose the most appropriate answer from the options given below:

Why was a change in the Bohr Model of atom required? Due to which important development$(s)$,was the concept of movement of an electron in an orbit replaced by the concept of probability of finding an electron in an orbital? What is the name given to the changed model of atom?

If a proton is accelerated to a velocity of $3 \times 10^7 \text{ ms}^{-1}$ which is accurate up to $\pm 0.5 \%$,then the uncertainty in its position will be $\ldots \ldots \ldots$ [mass of proton $= 1.66 \times 10^{-27} \text{ kg}$,$h = 6.6 \times 10^{-34} \text{ Js}$]

Which of the following statements is incorrect?