AP EAPCET 25-Aug-2021 Shift 2 Paper

Bohr's radius is equal to most probable distance between the nuclear and electron in H-atom in its ground states.
According to de-Broglie wavelength, the allowed any stationary orbit i.e. nλ=2πr
nλ=2π(5.29×10−11)(

n2

Z

)
λ=2π(5.29×10−11)×

n

Z

...(i)
where, r=5.29×10−11(

n2

Z

)
Putting Z=1 (For H-atom)
n=2 (For 2-orbit)
in Eq. (i), we get
λ=4π(5.29×10−11)m
λ=4×0.529π×10−10m
λ=2.116πÅ
Hence, de-Broglie wavelength in 2nd orbit is 2.116πÅ.