When a load of $10 \,kg$ is suspended on a metallic wire,its length increases by $2 \,mm$. The force constant of the wire is ........ $N/m$.

State Hooke's law.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Steel is used in the construction of buildings and bridges.
Reason $R$: Steel is more elastic and its elastic limit is high.
In the light of the above statements,choose the most appropriate answer from the options given below:

The increase in length is $l$ of a wire of length $L$ by the longitudinal stress. Then the stress is proportional to

When a force $F_1$ is applied on a metallic wire, the length of the wire is $L_1$. If a force $F_2$ is applied on the same wire, the length of the wire is $L_2$. The original length of the wire $L$ is

Match the physical quantities in Column-$I$ with the details given in Column-$II$ appropriately:

Column-$I$	Column-$II$
$(a)$ $\text{Stress} \propto \text{Strain}$	$(i)$ $M^1 L^{-1} T^{-2}$
$(b)$ $\text{Dimensional formula for compressibility}$	$(ii)$ $M^{-1} L^1 T^2$
	$(iii)$ $\text{Poisson's ratio}$
	$(iv)$ $\text{Hooke's law}$