The radius of the second Bohr orbit for hydrogen atom is : (Planck's Const. $\mathrm{h}=6.6262 \times 10^{-34} \mathrm{Js}$; mass of electron $=9.1091 \times 10^{-31} \mathrm{~kg}$; charge of electron $\mathrm{e}=1.60210 \times 10^{-19} \mathrm{C}$; permittivity of vacuum $\epsilon_{0}=8.854185 \times 10^{-12} \mathrm{~kg}^{-1} \mathrm{~m}^{-3} \mathrm{~A}^{2}$ )

JEE Main · 2017 · 02 Apr 2017 · Offline · Atomic Structure

The radius of the second Bohr orbit for hydrogen atom is :
(Planck's Const.

h = 6.6262 \times 1 0^{- 34} Js

; mass of electron

= 9.1091 \times 1 0^{- 31} kg

; charge of electron

e = 1.60210 \times 1 0^{- 19} C

; permittivity of vacuum

ϵ_{0} = 8.854185 \times 1 0^{- 12} kg^{- 1} m^{- 3} A^{2}

)

Answer: (D)

The Bohr radius grows as

n^{2}

, through

r_{n} = n^{2} a_{0}

with

a_{0} = 0.529

Angstrom. For the second orbit,

r_{2} = 4 \times 0.529 = 2.12

Angstrom.

JEE Main · 2017 · 02 Apr 2017 · Offline · Single correct option