When an electron in a hydrogen atom jumps from an infinite state to the first stationary state,the wavelength of the emitted radiation will be ...... (Rydberg constant = $1.097 \times 10^7 \ m^{-1}$):

The energy of an electron in the $n^{th}$ orbit of a hydrogen atom is given by:

Bohr’s atomic theory gave the idea of :

As an electron moves away from the nucleus,its potential energy

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$:
Assertion $A$: In the photoelectric effect,the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface.
Reason $R$: When the photon of any energy strikes an electron in the atom,transfer of energy from the photon to the electron takes place.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which among the following electron transitions $(n_2 \rightarrow n_1)$ in a $H$-atom results in the minimum change in its orbit radius $(r_2 - r_1)$?