The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?

The pressure that has to be applied to the ends of a steel wire of length $10 \ cm$ to keep its length constant when its temperature is raised by $100 \ ^\circ C$ is: (For steel,Young's modulus $Y = 2 \times 10^{11} \ N/m^2$ and coefficient of thermal expansion $\alpha = 1.1 \times 10^{-5} \ K^{-1}$)

$A$ stress of $1.5 \, kg.wt/mm^2$ is applied to a wire of Young's modulus $5 \times 10^{11} \, N/m^2$. The percentage increase in its length is

One end of a horizontal thick copper wire of length $2L$ and radius $2R$ is welded to an end of another horizontal thin copper wire of length $L$ and radius $R$. When the arrangement is stretched by applying forces at two ends,the ratio of the elongation in the thin wire to that in the thick wire is:

Consider a rod of length $1.0 \ m$ with a cross-sectional area of $0.50 \ cm^2$. The rod supports a $500 \ kg$ platform that hangs attached to the rod's lower end. What is the elongation of the rod under the stress, ignoring the weight of the rod (in $mm$)? Consider Young's modulus to be $10^{11} \ Pa$ and $g = 10 \ m \ s^{-2}$.

When a force of $4 \, N$ is applied to a wire,its length is $a \, m$. When a force of $5 \, N$ is applied,its length is $b \, m$. What will be its length when a force of $9 \, N$ is applied?