Q.

The energy of an electron in an orbit of the Bohr’s atom is -0.04E0 eV where E0 is the ground state energy. If L is the angular momentum of the electron in this orbit and h is the Planck’s constant, then 2πLh=_____.   [2026]

1 5  
2 2  
3 6  
4 4  

Ans.

(1)

Angular momentum L=nh2π

n=2πLh

Energy E=-13.6n2Z2

E-E0n2=-0.04E0

n2=25,  n=5