Suddenly a boy comes and sits on a rotating round table, what will be the effect on the angular velocity of the table?

When a boy sits on a rotating round table, the angular velocity of the table will decrease. This change occurs due to the conservation of angular momentum. When the boy adds his mass to the system, the moment of inertia increases. Since angular momentum is conserved in the absence of external torques, the angular velocity must decrease to compensate for the increased moment of inertia. This phenomenon is akin to an ice skater extending their arms to slow down their spin while conserving angular momentum. Hence, the correct answer is [A] Will decrease. This effect is predictable based on fundamental principles of rotational motion and applies universally regardless of specific table or boy characteristics, making the change in angular velocity predictable and consistent.