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NEET Physics Atoms Questions Solved

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to

(a) n (b) $\frac{n^{2}}{Z^{2}}$
(c) $\frac{n^{2}}{Z}$ (d) $\frac{Z}{n}$

(b) $T = \frac{2 πr}{v}$ ; r = radius of nth orbit= $\frac{n^{2} h^{2}}{{πmZe}^{2}}$

v = speed of $e^{-}$ in nth orbit = $\frac{{ze}^{2}}{2 ε_{0} nh}$

$∴ T = \frac{4 ε_{0}^{2} n^{3} h^{3}}{{mZ}^{2} e^{4}} \Rightarrow T \propto \frac{n^{3}}{Z^{2}}$

Difficulty Level:

(1)
12%
(2)
42%
(3)
38%
(4)
10%

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