What is the Young's modulus and bulk modulus for a perfect rigid body?

$A$ rod $BC$ of negligible mass is fixed at end $B$ and connected to a spring at its natural length having spring constant $K = 10^4 \ N/m$ at end $C$,as shown in the figure. For the rod $BC$,length $L = 4 \ m$,area of cross-section $A = 4 \times 10^{-4} \ m^2$,Young's modulus $Y = 10^{11} \ N/m^2$ and coefficient of linear expansion $\alpha = 2.2 \times 10^{-4} \ K^{-1}$. If the rod $BC$ is cooled from temperature $100^oC$ to $0^oC$,then find the decrease in length of the rod in centimeters (closest to the integer).

The interatomic distance for a metal is $3 \times 10^{-10} \ m$. If the interatomic force constant is $3.6 \times 10^{-9} \ N/\mathring{A}$,then the Young's modulus in $N/m^2$ will be:

If Young's modulus of iron is $2 \times 10^{11} \ N/m^2$ and the interatomic spacing between two molecules is $3 \times 10^{-10} \ m$,the interatomic force constant is ......... $N/m$.

$A$ load of $1 \,kg$ weight is attached to one end of a steel wire of area of cross-section $3 \,mm^2$ and Young's modulus $10^{11} \,N/m^2$. The other end is suspended vertically from a hook on a wall, then the load is pulled horizontally and released. When the load passes through its lowest position, the fractional change in length is $(g = 10 \,m/s^2)$.

Stress required in a wire to produce $0.1\%$ strain is $4 \times 10^8 \, N/m^2$. Its Young's modulus is $Y_1$. If stress required in another wire to produce $0.3\%$ strain is $6 \times 10^8 \, N/m^2$,and its Young's modulus is $Y_2$,which relation is correct?