Mark the wrong statement.

If the breaking force for a given wire is $F$, and the thickness of the wire is doubled, then the breaking force will be:

$A$ string of cross-sectional area $4 \times 10^{-6} \, m^{2}$ and length $0.5 \, m$ is connected to a rigid body of mass $2 \, kg$. The body is rotated in a vertical circular path of radius $0.5 \, m$. The body acquires a speed of $5 \, m/s$ at the bottom of the circular path. The strain produced in the string when the body is at the bottom of the circle is $\dots \times 10^{-5}$. (Use Young's modulus $Y = 10^{11} \, N/m^{2}$ and $g = 10 \, m/s^{2}$)

Statement $(A)$ For an ideal liquid,the bulk modulus is infinite and the shear modulus is zero.
Statement $(B)$ The volume contraction of a metal cube of bulk modulus $140 \text{ GPa}$ and side length $10 \text{ cm}$,when subjected to a hydraulic pressure of $7 \times 10^6 \text{ Pa}$,is $-0.05 \text{ m}^3$.
Statement $(C)$ $A$ spiral spring is stretched by a weight attached to it. The strain is tensile.

$A$ substance breaks down by a stress of $10^6 \ N/m^2$. If the density of the material of the wire is $3 \times 10^3 \ kg/m^3$,then the length of the wire of the substance which will break under its own weight when suspended vertically,is ......... $m$.

The two thigh bones (femurs),each of cross-sectional area $10 \; cm^{2}$,support the upper part of a human body of mass $40 \; kg$. Estimate the average pressure sustained by the femurs.