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Wave Optics

Question
CBSEENPH12039804
Wired Faculty App

Consider 3rd orbit of He+ (Helium), using non-relativistic approach, the speed of electron in this orbit will be (given K= 9 x 109 constant, Z=2 and h (Planck's constant = 6.6 x 10-34 Js-1

  • 2.92 x 106 m/s

  • 1.46 x 106 m/s

  • 0.73 x 106 m/s

  • 3.0 x 108 m/s

Solution

B.

1.46 x 106 m/s

Energy of electron in the 3rd orbit of He+ is
straight E subscript 3 space equals space minus 13.6 space straight x space straight Z squared over straight n squared eV space equals space minus 13.6 space straight x space 4 over 3 squared eV space equals space minus 13.6 space straight x space 4 over 9 straight x space 16 space straight x space 10 to the power of negative 19 end exponent space straight J From space Bohr apostrophe straight s space model comma straight E subscript 3 space equals negative KE subscript 3 space equals space minus 1 half straight m subscript straight e straight V squared rightwards double arrow space 1 half space straight x space 9.1 space straight x space 10 to the power of negative 31 end exponent space straight x space straight v squared space equals space minus 13.6 space straight x space 4 over 9 space straight x space 1.6 space straight x space 10 to the power of negative 19 end exponent straight v squared space equals space fraction numerator 136 space straight x space 16 space straight x space 4 space straight x space 2 straight x space 10 to the power of negative 11 end exponent over denominator 9 space straight x space 91 end fraction or space straight v equals space 1.46 space straight x space 10 to the power of 6 space straight m divided by straight s

Some More Questions From Wave Optics Chapter

The positively charged part of the atom possesses most of the mass in ___________ (Rutherford's model/both the models).

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