A thin copper wire of length $L$ increase in length by $1\%$ when heated from temperature $T_1$ to $T_2$. What is the percentage change in area when a thin copper plate having dimensions $2L\times L$ is heated from $T_1$ to $T_2$ ? ....... $\%$
$1$
$2$
$3$
$4$
A steel tape gives correct measurement at $20^o C$. A piece of wood is being measured with the steel tape at $0^o C$. The reading is $25 \,\,cm$ on the tape, the real length of the given piece of wood must be:
$5$ litre of benzene weighs
A metallic bar of Young's modulus, $0.5 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}$ and coefficient of linear thermal expansion $10^{-5}{ }^{\circ} \mathrm{C}^{-1}$, length $1 \mathrm{~m}$ and area of cross-section $10^{-3} \mathrm{~m}^2$ is heated from $0^{\circ} \mathrm{C}$ to $100^{\circ} \mathrm{C}$ without expansion or bending. The compressive force developed in it is :
A circular metallic disc of radius $R$ has a small circular cavity of radius $r$ as shown in figure. On heating the system
When a bimetallic strip is heated, it