MCQ
A uniform metallic rod rotates about its perpendicular bisector with constant angular speed. If it is heated uniformly to raise its temperature slightly:
  • A
    Its speed of rotation increases.
  • Its speed of rotation decreases.
  • C
    Its speed of rotation remains same.
  • D
    Its speed increases because its moment of inertia increases.

Answer

Correct option: B.
Its speed of rotation decreases.
On heating a uniform metallic rod its length will increase so moment of inertia of rod increased from $I_1$ to $I_2$
$($i.e., $I_1 \text{I}_1\omega_1=\text{I}_2\omega_2)$
$\because\ \text{I}_1<\text{I}_2\Rightarrow\omega_1>\omega_2,$
so angular speed decreases.

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

A hydrogen atom in ground state absorbs $10.2 eV$ of energy. The orbital angular momentum of the electron is increased by:
 
A man slides down a light rope whose breaking strength is $\eta$ times the weight of man $(\eta<1)$. The maximum acceleration of the man so that the rope just breaks is ........
Ten tuning forks are arranged in increasing order of frequency in such a way that any two consecutive tuning forks produce $4$ beats per second. The highest frequency is twice that of the lowest. Possible highest and lowest frequencies (in $Hz$ ) are ................
The dimensions of ${e^2}/4\pi {\varepsilon _0}hc$, where $e,\,{\varepsilon _0},\,h$ and $c$ are electronic charge, electric permittivity, Planck’s constant and velocity of light in vacuum respectively
A bullet moving with a uniform velocity v, stops suddenly after hitting the target and the whole mass melts be $m$, specific heat $S,$ initial temperature $25°C$ melting point $ 475°C$ and the latent heat $L.$ Then $v$ is given by
A car is moving at a speed of $40 \,m / s$ on a circular track of radius $400 \,m$. This speed is increasing at the rate of $3 \,m / s ^2$. The acceleration of car is ....... $m / s ^2$
$Assertion :$ The pitch of wind instruments rises and that of string instruments falls as an orchestra warms up.
$Reason :$ When temperature rises, speed of sound increases but speed of wave in a string fixed at both ends decreases.
A product from a chemical industry passes through three states $-$ gas, liquid, solid. The product is initially formed in gaseous state which is then liquefied and finally solidified. For same mass $($say $5g)$ which state has maximum internal energy?
A uniform sphere of weight $W$ and radius $5\, cm$ is being held by a string as shown in the figure. The tension in the string will be
A tuning fork $A$ of unknown frequency produces $5\, beats/s$ with a fork of known frequency $340\, Hz$. When fork $A$ is filed, the beat frequency decreases to $2\, beats/s.$ What is the frequency of fork $A$ ? (in $Hz$)