A metal rod of length ' $L$ ' and mass ' $m$ ' is pivoted at one end. A thin disk of mass ' $M$ ' and radius $'R'$ $( < L)$ is attached at its center to the free end of the rod. Consider two ways the disc is attached: (case $A$) The disc is not free to rotate about its center and (case $B$) the disc is free to rotate about its center. The rod-disc system performs $SHM$ in vertical plane after being released from the same displaced position. Which of the following statement$(s)$ is (are) true? $Image$

$(A)$ Restoring torque in case $A =$ Restoring torque in case $B$

$(B)$ Restoring torque in case $A < $ Restoring torque in case $B$

$(C)$ Angular frequency for case $A > $ Angular frequency for case $B$.

$(D)$ Angular frequency for case $A < $ Angular frequency for case $B$.

IIT 2011, Advanced
Download our app for free and get startedPlay store
Restoring torque is same in both cases,

$\propto=\frac{ T }{ I }=-\omega^2 \theta$

In case $A$ the moment of Inertia is more as compared to $B$ , So

$\omega_{ B } > \omega_{ A }$

$A$ and $D$ are correct answer

art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    A particle undergoing simple harmonic motion has time dependent displacement given by $x(t)\, = \,A\,\sin \,\frac{{\pi t}}{{90}}$. The ratio of kinetic to potential energy $o$ the particle at $t=210\,s$ will be
    View Solution
  • 2
    The variation of displacement with time of a particle executing free simple harmonic motion is shown in the figure. The potential energy ${U}({x})$ versus time $({t})$ plot of the particle is correctly shown in figure:
    View Solution
  • 3
    A mass $m$ attached to a spring oscillates with a period of $3\,s$. If the mass is increased by $1\,kg$ the period increases by $1\,s$. The initial mass $m$ is
    View Solution
  • 4
    The energy of a particle executing simple harmonic motion is given by $E = Ax^2 + Bv^2$, where $x$ is the displacement from mean position $x = 0$ and $v$ is the velocity of the particle at $x$ then choose the incorrect statement
    View Solution
  • 5
    What effect occurs on the frequency of a pendulum if it is taken from the earth surface to deep into a mine
    View Solution
  • 6
    The period of oscillation of a simple pendulum of length $L$ suspended from the roof of a vehicle which moves without friction down an inclined plane of inclination $\alpha$, is given by
    View Solution
  • 7
    The height of a swing changes during its motion from $0.1\, m$ to $2.5\, m$. The minimum velocity of a boy who swings in this swing is ..... $m/s$
    View Solution
  • 8
    Two springs have spring constants ${K_A}$ and ${K_B}$ and ${K_A} > {K_B}$. The work required to stretch them by same extension will be
    View Solution
  • 9
    If displacement $x$ and velocity $v$ are related as $4v^2 = 25 -x^2$ in a $SHM$. Then time Period of given $SHM$ is (Consider $SI\, units$)
    View Solution
  • 10
    A vibratory motion is represented by $x = 2A\,\cos \omega t + A\,\cos \,\left( {\omega t + \frac{\pi }{2}} \right) + A\,\cos \,\left( {\omega t + \pi } \right)$ $ + \frac{A}{2}\,\cos \left( {\omega t + \frac{{3\pi }}{2}} \right)$. The resultant amplitude of the motion is
    View Solution