Browse Questions

# Moment of inertia of a square lamina about one of the diagonals is :

$\begin {array} {1 1} (a)\;\frac{Ml^2}{6} & \quad (b)\;\frac{Ml^2}{12} \\ (c)\;\frac{Ml^2}{3} & \quad (d)\;\frac{Ml^2}{24} \end {array}$

Using perpendicular Axes theorems
$Iz=I_{xx'}+I_{yy'}$
$\large\frac{Ml^2}{6}$$=2 I xx^{1} \qquad \bigg[I_{xx'}=I_{yy'} \;by\;symmetry\bigg]$
$\therefore I_{xx^1}=\large\frac{Ml^2}{12}$