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 answer
    A
    $2.5 \mathrm{~kg} \mathrm{~m}^{2}$
  • 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'.

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