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MHT CET202523 Apr 2025Morning ShiftChemistryStructure of AtomActual

What is the numerical value of angular momentum for an electron in first orbit of hydrogen atom ? ( h =6.626 10⁻³⁴ Js )

Options

  1. A1.05 10⁻³⁴
  2. B2 10 10⁻³⁴
  3. C3.16 10⁻³⁴
  4. D4.22 10⁻³⁴

Correct answer

A. 1.05 10⁻³⁴

Step-by-step solution

The angular momentum of an electron in Bohr's stationary orbit is quantized as L = n h 2 , where n is the principal quantum number and h is Planck's constant ( 6.626 10⁻³⁴ Js ). For the first orbit, n = 1 , yielding L = 6.626 10⁻³⁴ 2 Js . Numerical evaluation gives L 1.0545 10⁻³⁴ Js , which rounds to 1.05 10⁻³⁴ Js . This matches option A .

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