Given below are two statement : one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : When a rod lying freely is heated, no thermal stress is developed in it.
Reason $R :$ On heating the length of the rod increases.
In the light of the above statements, choose the correct answer from the options given below
Both $A$ and $R$ are true but $R$ is $NOT$ the correct explanation of $A$
$A$ is false but $R$ is true
$A$ is true but $R$ is false
Both $A$ and $R$ are true and $R$ is the correct explanation of $A$
What is areal expansion ? Give definition and unit of coefficient of areal expansion.
A blacksmith fixes iron ring on the rim of the wooden wheel of a horse cart. The diameter of the rim and the iron ring are $5.243\; m$ and $5.231\; m$, respectively at $27^oC$. To what temperature (in $^oC$) should the ring be heated so as to fit the rim of the wheel?
On which of the following four processes, does the functioning of a bimetallic strip depends
$(i)$ Radiation
$(ii)$ Energy conversion
$(iii)$ Melting
$(iv)$ Thermal expansion
A pendulum clock (fitted with a small heavy bob that is connected with a metal rod) is $5\, seconds$ fast each day at a temperature of $15\,^oC$ and $10\,seconds$ slow at a temperature of $30\,^oC$. The temperature at which it is designed to give correct time, is ........ $^oC$
In a vertical $U-$tube containing a liquid, the two arms are maintained at different temperatures ${t_1}$ and ${t_2}$. The liquid columns in the two arms have heights ${l_1}$ and ${l_2}$ respectively. The coefficient of volume expansion of the liquid is equal to