Q46 / 201 · NTA Abhyas (NEET) 2020 · Physics · Atomic Physics

The angular momentum of an electron in hydrogen atom is hπ. The kinetic energy of the electron is

  • A
    13.6 eV
  • Correct answer
    B
    3.4 eV
  • C
    1.51 eV 
  • D
    0.85 eV

Solution

The angular momentum of an electron in hydrogen atom =hπ .

As we know, from Bohr's second postulate,

mvr=hπ⇒v=hπmr ...(i)

Now, kinetic energy of electron

=12mv2=12m×hπmr2 [from Equation (i)]

=h22π2mr2

=6.63×10-3422×3.142×9.1×10-31×5.3×10-112×1.6×10-19

=3.4 eV

Hence, the correct answer is option: 'B'.

More Atomic Physics Questions