Q. If all of a sudden the radius of the earth decreases, then
A) The angular momentum of the earth will become greater than that of the sun
B) The angular speed of the earth will increase
C) The periodic time of the earth will increase
D) The energy and angular momentum will remain constant
Explanation
(b) If radius of earth decreases then its M.I. decreases
As $L = I\omega\ \therefore\omega \propto \frac{1}{I}$ [$L =$ constant]
$i.e.$ angular velocity of the earth will increase
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.