Name the property of a material by which it opposes the deformation.

Two wires as shown in the figure below, made of steel, have a breaking stress of $12 \times 10^8 \text{ N/m}^2$. The area of cross-section of the upper wire is $0.008 \text{ cm}^2$ and that of the lower wire is $0.004 \text{ cm}^2$. The maximum mass that can be added to the pan without breaking any wire is . . . . . . kg. (Take $g = 10 \text{ m/s}^2$)

Two equal and opposite forces each $F$ act on a rod of uniform cross-sectional area $a$ as shown in the figure. The shearing stress on the section $AB$ will be

Explain what is stress? Write its unit and dimensional formula.

What is stress? Write its unit and dimensional formula.

The length of a metallic wire is $\ell_{1}$ when the tension in it is $T_{1}$. It is $\ell_{2}$ when the tension is $T_{2}$. The original length of the wire will be ...... .