Identify the incorrect statement/s. A. The maximum number of electrons that can be accommodated in an atom, in which the largest Principal quantum number value is 4 , is 54 . B. According to Rydberg, all series of lines in Hydrogen spectrum can be described by the equation: $\dfrac{1}{\lambda}=109677\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right) \mathrm{cm}^{-1}$ where $\left(n_1 <n_2\right)$

For statement A, the maximum number of electrons in an atom with principal quantum number $n=4$ is determined by the total number of orbitals available. The orbitals are $1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f$. The number of orbitals is $1 + 1 + 3 + 1 + 3 + 5 + 1 + 3 + 5 + 7 = 30$. Each orbital can hold 2 electrons, so the maximum capacity is $30 \times 2 = 60$ electrons. Thus, statement A is incorrect.

For statement B, the Rydberg formula for the hydrogen spectrum is given by $\dfrac{1}{\lambda} = R_H \left( \dfrac{1}{n_1^2} - \dfrac{1}{n_2^2} \right)$, where $R_H \approx 109677 \text{ cm}^{-1}$. This equation describes all series of lines in the hydrogen spectrum for $n_1 < n_2$. Thus, statement B is correct.

Answer: Only A