The number of revolutions done by an electron in one second in the first orbit of a hydrogen atom is

• Correct answer
  A

  $6.57\times {10}^{15}$
• B

  $6.57\times {10}^{13}$
• C

  $6.57\times {10}^{11}$
• D

  $6.57\times {10}^{14}$

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