Question

In the rectangular lamina show in the $AB=BC/2$. The moment of inertia of the is minimum along the axis passing through :

• A. $AB$
• B. $BC$
• C. $EG$
• D. $FH$

Answer 1

Answer: (D)

$FH$

Ref. Image I

Moment of inertia $\sum m_i{r}_i^2$

$\Rightarrow$ moment of Inertia $\alpha r^2$

$\ast$ moment of Inertia is depend on the distance from the axis

$\ast$ more the distance more moment of Inertia

From the given options

Assuming $AD$ as $l\Rightarrow AB=\frac{l}{2}$

Ref. image II

as $r$ i.e. distance is less in $FH$ axis moment of inertia is less about $FH$ axis.