Atomic Models — Prelims Questions

According to Bohr's model, the radius of the $n^{th}$ orbit of a hydrogen atom is proportional to:

Which of the following statements is NOT a postulate of Bohr's atomic model?

The energy of an electron in the first Bohr orbit of a hydrogen atom is -13.6 eV. What is the energy of an electron in the second Bohr orbit of a $\text{He}^+$ ion?

Rutherford's alpha-particle scattering experiment led to the conclusion that:

Calculate the wavelength of the first line in the Balmer series of the hydrogen spectrum. (Given: Rydberg constant $R_H = 1.097 \times 10^7 \text{ m}^{-1}$)

Which atomic model is often referred to as the 'plum pudding' model?