Which of the following statement is true regarding Bohr's model of hydrogen atom ?
(I) Orbiting speed of electrons decreases as if falls to discrete orbits away from the nucleus.
(II) Radii of allowed orbits of electrons are proportional to the principle quantum number.
(III) Frequency with which electrons orbit around the nucleus in discrete orbits is inversely proportional to the principle quantum number.
(IV) Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits.
Selected the correct answer using the codes given below:

Options

A. I and III
B. II and IV
C. I, II and III
D. II, III and IV

Answer

A

Explanation

In case of Bohr's model of hydrogen atom, orbital speed varies inversely as the radius of the orbit and energy increases with increases in equantum number.
Further frequency `= (v)/(2pir)`
Here `v prop (1)/(n)` and `r prop n^(2)`
Frequency `prop (1)/(n)`