MCQ
In a rectangle $ABCD\,\,(BC = 2AB)$. The moment of inertia along which axis will be minimum
  • A
    $BC$
  • B
    $BD$
  • C
    $HF$
  • $EG$

Answer

Correct option: D.
$EG$
d
The moment of inertia will be minimum about that axis, which is passing through the center of mass.

$I_{E G}=\frac{M B^{2}}{12}$

$I_{F H}=\frac{M(2 B)^{2}}{12}=\frac{M B^{2}}{6}$

$M. I.$ of the rectangular plate about its diagonal $I_{B D}=\frac{M B^{2} L^{2}}{6\left(B^{2}+L^{2}\right)}=\frac{M B^{2} \times 4 B^{2}}{6\left(B^{2}+4 B^{2}\right)}=\frac{2}{15} M B^{2}=\frac{M B^{2}}{7.5}$

$M. I.$ about $E G$ is minimum.

$\mathrm{OR}$

By observation, distribution of mass is the nearest about axis $E G .$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Quality of a musical note depends on
A particle moves along $X-$axis in such a way that its coordinate $X$ varies with time $t$ according to the equation $x = (2 - 5t + 6{t^2})\,m$. The initial velocity of the particle is.......$m/s$
The equation of a wave travelling on a string is $y=4 \sin \left[\frac{\pi}{2}\left(8 t-\frac{x}{8}\right)\right]$ where $x , y$ are in cm and t in second. The velocity of the wave is
A man of mass $60 \,kg$ is standing on a boat of mass $140 \,kg$, which is at rest in still water. The man is initially at $20 \,m$ from the shore. He starts walking on the boat for $4 \,s$ with constant speed $1.5 \,m / s$ towards the shore. The final distance of the man from the shore is .......... $m$
A perfect gas at $27^\circ C$ is heated at constant pressure to $327^\circ C$. If original volume of gas at $27^\circ C$ is $V$ then volume at $327^\circ C$ is
A particle is moving with speed $v= b\sqrt x$ along positive $x-$ axis. Calculate the speed of the particle at time $t = \tau$ (assume that the particle is at origin at $t = 0$ ).
The molar specific heat at constant pressure of an ideal gas is $\Big(\frac{7}{2}\text{R}\Big).$ The ratio of specific heat at constant pressure to that at constant volume is:
Two particles execute $SHM$ of same amplitude of $20\, cm$ with same period along the same line about the same equilibrium position. The maximum distance between the two is $20\, cm.$ Their phase difference in radians is
A container contains $32 \,g$ of $O _2$ at a temperature $T$. The pressure of the gas is $P$. An identical container containing $4 g$ of $H _2$ at a temperature $2 T$ has a pressure of ............
The length of an elastic string is a metre when the longitudinal tension is $4\, N$ and $b$ metre when the longitudinal tension is $5\, N$. The length of the string in metre when the longitudinal tension is $9\, N$ is