Question

The S.I. unit of Moment of inertia is:

• A. kg/$m^2$
• B. kg$m^2$
• C. N/$m^2$
• D. ${Nm}^2$

Answer 1

The correct option is B kg$m^2$

For a point mass, the Moment of Inertia is the mass times the square of the perpendicular distance to the rotation reference axis and can be expressed as.

$I=m{r}^2$

Unit for mass is $Kg$

unit for distance is metre.

Unit for moment of inertia ill be $Kg{m}^2$

Dimensions are $\left[M{L}^2{T}^0\right]$

All other options have dimensions as $\left[M{L}^{-2}{T}^0\right]$ , $\left[M{L}^{-1}{T}^{-2}\right]$ , $\left[M{L}^3{T}^{-2}\right]$ for 1, 3 and 4 options respectively.