JEE Main 10 Apr 2019 Paper 2 Solved Paper

In Li++ electron in first Bohr orbit is excited to a level by a radiation of wavelength λ .when the ion gets deexcited to the ground state in all possible ways (including intermediate emissions)a total of six spectral lines are observed. what is the value of λ ?{Given h=6.63×10−34Js;c=3×108ms−1}