Which of the following statements are true regarding Bohr's model of hydrogen atom.

(I) Orbiting speed of electron decreases as it shifts to discrete orbits away from the nucleus.

(II) Radii of allowed orbits of electron are proportional to the principal quantum number.

(III) Frequency with which electrons orbits around the nucleus in discrete orbits is inversely proportional to the principal quantum number.

(IV) Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits.

Select correct answer using the codes given below Codes :

I and III

Orbital speed varies inversely as the radius of the orbit. Energy increases with the increase in quantum number.