Q116 / 150 · MHT CET 2009 · Physics
The moments of inertia of two freely rotating bodies $A$ and $B$ are $I_{A}$ and $I_{B}$ respectively. $I_{A}>I_{B}$ and their angular momenta are equal. If $K_{A}$ and $K_{B}$ are their kinetic energies, then
- A$K_{A}=K_{B}$
- B$K_{A} \neq K_{B}$
- Correct answerC$K_{A} < K_{B}$
- D$K_{A}=2 K_{B}$
Solution
Kinetic energy $E=\frac{L^{2}}{2 I}$ If angular momenta are equal, then $E \propto \frac{1}{I}$ Kinetic energy $E=K$ (given in problem)
$$
\text { If } I_{A}>I_{B} \text { then } K_{A} < K_{B}
$$
Hence, the correct answer is option: 'C'.