Q93 / 125 · BITSAT 2011 · Physics
A constant torque of $31.4 \mathrm{~N}-\mathrm{m}$ is exerted on a pivoted wheel. If angular acceleration of wheel is $4 \pi \mathrm{rad} / \mathrm{s}^{2},$ then the moment of inertia of the wheel is
- Correct answerA$2.5 \mathrm{~kg} \mathrm{~m}^{2}$
- B$3.5 \mathrm{~kg} \mathrm{~m}^{2}$
- C$4.5 \mathrm{~kg} \mathrm{~m}^{2}$
- D$5.5 \mathrm{~kg} \mathrm{~m}^{2}$
Solution
$I=\frac{\tau}{\alpha}=\frac{31.4}{4 \pi}=\frac{31.4}{4 \times 3.14}=2.5 \mathrm{~kg} \mathrm{~m}^{2}$.
Hence, the correct answer is option: 'A'.