Consider that an electron is revolving in an excited state of Hydrogen atom with velocity 25.6 105 ms-1. The radius of the orbit is x 10-9 m. The value of x is: [Take the mass of electron to be 9 10-31 kg, charge of electron = -1.6 10-19 C and 14 0 = 9 109 Nm2C-2]
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Answer
(1) 1
Solution
The electrostatic force provides the necessary centripetal force for the revolving electron:
m v2r = 14 0 e2r2 r = 14 0 e2m v2
Substitute the given values:
r = 9 109 (1.6 10-19)29 10-31 ( 25.6 105)2 = 9 109 2.56 10-389 10-31 25.6 1010 = 10-9 m
Comparing with r = x 10-9 m, we get x = 1.
Answer: (1)