During the transition of electron from state A to state C of a Bohr atom, the wavelength of emitted…
- $4000 Å$
- $2000 Å$
- $3000 Å$
- $6000 Å$
Solution

$\frac{h c}{\lambda_1}=E_0 z^2\left(\frac{1}{n_c^2}-\frac{1}{n_A^2}\right)$....(i)
And $\frac{h c}{\lambda_2}=E_0 z^2\left(\frac{1}{n_c^2}-\frac{1}{n_B^2}\right)$
So for $A$ and $B$....(ii)
$\frac{h c}{\lambda_3}=E_0 z^2\left(\frac{1}{n_B^2}-\frac{1}{n_A^2}\right)$
Clearly subtracting equation (ii) from equation (i)
$\begin{aligned}
& h c\left[\frac{1}{\lambda_1}-\frac{1}{\lambda_2}\right]=E_0 z^2\left[\frac{1}{n_B^2}-\frac{1}{n_A^2}\right]=\frac{h c}{\lambda_3} \\ & \Rightarrow \frac{1}{\lambda_3}=\frac{1}{\lambda_1}-\frac{1}{\lambda_2} \Rightarrow \frac{1}{\lambda_3}=\frac{(6000-2000)}{6000 \times 2000}=\frac{1}{3000} \\ & \lambda_3=3000 Å
\end{aligned}$
Asked in: JEE Main 2025 (24 Jan Shift 1)