Q.

According to Bohr's theory, the moment of momentum of an electron revolving in 4th orbit of hydrogen atom is          [2024]

1 h2π  
2 8hπ  
3 2hπ  
4 hπ  

Ans.

(3)       

            Moment of momentum or angular momentum, L=nh2π

             put n=4

             L=4h2π=2hπ