Q143 / 180 · JIPMER 2017 · Physics

$A B C$ is right angled triangular plane of uniform thickness. The sides are such that $A B \gt B C$ as shown in figure. $I_1, I_2, I_3$ are moments of inertia about $A B, B C$ and $A C$, respectively. Then which of the following relations is correct? Figure

  • A
    $I_1=I_2=I_3$
  • Correct answer
    B
    $I_2 \gt I_1 \gt I_3$
  • C
    $I_3 \lt I_2 \lt I_1$
  • D
    $I_3 \gt I_1 \gt I_2$

Solution

The moment of inertia of a body about an axis depends not only on the mass of the body but also on the distribution of mass about the axis. For a given body mass is same, so it will depend only on the distribution of mass about the axis. The mass is farthest from axis $B C$, so $I_2$ is maximum mass is nearest to axis $A C$, so $I_3$ is minimum. Hence, the correct sequence will be $I_2 \gt I_1 \gt I_3$

Hence, the correct answer is option: 'B'.

Relevant Questions