If the orbital speed of a body revolving in a circular path near the surface of the earth is $8 \mathrm{kms}^{-1}$, then the orbital speed of a body revolving around the earth in a circular orbit at height of $19,200 \mathrm{~km}$ from the surface of earth is (Radius of the earth $=6400 \mathrm{~km}$ )

• Correct answer
  A

  $4 \mathrm{kms}^{-1}$
• B

  $6 \mathrm{kms}^{-1}$
• C

  $7.5 \mathrm{kms}^{-1}$
• D

  $9 \mathrm{kms}^{-1}$

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