Angular Momentum and Conservation of Angular Momentum: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Angular Momentum and Conservation of Angular Momentum. Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true, stating the conservation of angular momentum. Reason (R) is true, defining the angular impulse-momentum theorem \(\Delta \vec{\text{L}} = int \vec{\tau} \text{dt}\). If \(\vec{\tau}_{ext} = 0\), then \(\Delta \vec{\text{L}} = 0\), so \(\vec{\text{L}}\) is constant. (R) correctly explains (A).