Select the incorrect graph for the velocity of an electron $(e^-)$ in an orbit vs. $Z$,$\frac{1}{n}$,and $n$.

The difference between the radii of $3^{rd}$ and $4^{th}$ orbits of $Li^{2+}$ is $\Delta R_{1}$. The difference between the radii of $3^{rd}$ and $4^{th}$ orbits of $He^{+}$ is $\Delta R_{2}$. Ratio $\Delta R_{1} : \Delta R_{2}$ is :

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is = ....... (Bohr radius $a_0$)

Which one of the following about an electron occupying the $1s$ orbital in a hydrogen atom is incorrect? (The Bohr radius is represented by $a_0$)

In a hydrogen atom,the energy of an $e^-$ in an orbital is given by $E = \frac{-constant}{n^2} \ (kJ \ mol^{-1})$. Which of the following properties is constant according to the given equation?

If in a hydrogen atom,an electron jumps from the $3^{rd}$ Lyman line to the $1^{st}$ Lyman line,then the obtained wavelength is: