Question

A uniform metallic rod rotates about its perpendicular bisector with constant angular speed. If it is heated uniformly to raise its temperature slightly
A. its speed of rotation increases
B. its speed of rotation decreases
C. its speed of rotation remains same
D. its speed increases because its moment of inertia increases

Answer 1

Correct Answer - B
When a metallic rod is heated it expands. Its moment of inertia (l) about a perpendicular bisector increases. Ac cording to law of conservation of angular momentum, its angular speed `(omega)` decreases, since `omega prop 1//l` (ac cording to law of conservation of angular momentum).