Embibe Experts Solutions for Exercise 3: Assignment

Two exactly similar wires of steel and copper are stretched by equal forces. If the total elongation is $2 \mathrm{cm},$ then how much is the elongation in steel and copper wire respectively? Given, $Y_{\mathrm{steel}}=20\times {10}^{11} \mathrm{dyne} {\mathrm{cm}}^{–2}, Y_{\mathrm{copper}}=12\times {10}^{11}\mathrm{dyne} {\mathrm{cm}}^{–2}.$

What is the greatest length of copper wire that can hang without breaking?

Breaking stress $=7.2\times {10}^7 \mathrm{N} {\mathrm{m}}^{–2},$ Density of copper $=7.2 \mathrm{g} {\mathrm{cc}}^{–1}, g=10 \mathrm{m} {\mathrm{s}}^{–2}$

Which of the following is the graph showing stress-strain variation for elastomers?

A spherical ball contracts in volume by $0.01\%$ when subjected to a normal uniform pressure of $100$ atm. The Bulk modulus of its material is

Select the incorrect option

A student performs an experiment to determine the Young's modulus of a wire, exactly $2 \mathrm{m}$ long, by Searle's method. In a particular reading, the student measures the extension in the length of the wire to be $0.8 \mathrm{mm}$ with an uncertainty of $\pm 0.05 \mathrm{mm}$ at a load of exactly $1.0 \mathrm{kg}.$ The student also measures the diameter of the wire to be $0.4 \mathrm{mm}$ with an uncertainty of $\pm 0.01 \mathrm{mm}.$ Take $g=9.8 \mathrm{m} {\mathrm{s}}^{–2}$ (exact). The Young's modulus obtained from the reading is

A steel wire $4.0 \mathrm{m}$ in length is stretched through $2.0 \mathrm{mm}.$ The cross-sectional area of the wire is $2.0{ \mathrm{mm}}^2.$ If Young's modulus of steel is $2.0\times {10}^{11} \mathrm{N} {\mathrm{m}}^{–2}$ then elastic potential energy stored per unit volume is$N\times {10}^3 \mathrm{J} {\mathrm{m}}^{–3},$ then $N$ is _____.

For a given material, the Young's modulus is $2.4$ times its modulus of rigidity. Its Poisson's ratio is _____.