What is the shape of the graph of stress $\to$ strain up to the elastic limit?

$A$ lift of mass $1600 \text{ kg}$ is supported by a thick iron wire. If the maximum stress which the wire can withstand is $4 \times 10^8 \text{ N/m}^2$ and its radius is $4 \text{ mm}$, then the maximum acceleration the lift can take is . . . . . . $\text{m/s}^2$. (Take $g = 10 \text{ m/s}^2$ and $\pi = 3.14$)

$A$ force of $1000 \, N$ is required to break a copper wire of radius $1 \, mm$. What force is required to break a copper wire of radius $2 \, mm$?

When is the force between atoms attractive? When is it repulsive?

The pointer reading versus load graph for a spring balance is as given in the figure. The spring constant is ........ $kg/cm$.

$A$ wire can be broken by applying a load of $20 \, kg$ weight. The force required to break the wire of twice the diameter is .......... $kg \, wt$.