An area of cross-section of rubber string is 2,c{m^2} . Its length is doubled when stretched with a

English

Gujarati

Hindi

8.Mechanical Properties of Solids

easy

An area of cross-section of rubber string is $2\,c{m^2}$. Its length is doubled when stretched with a linear force of $2 \times {10^5}$dynes. The Young's modulus of the rubber in $dyne/c{m^2}$ will be

A

$4 \times {10^5}$

B

$1 \times {10^5}$

C

$2 \times {10^5}$

D

$1 \times {10^4}$

Solution

(b) If length of the wire is doubled then strain $= 1$

Y = ${\rm{Stress}} = \frac{{{\rm{Force}}}}{{{\rm{Area}}}}$= $\frac{{2 \times {{10}^5}}}{2} = {10^5}\frac{{dyne}}{{c{m^2}}}$

Standard 11

Physics

Share

Similar Questions

The length of an elastic string is a metre when the longitudinal tension is $4\, N$ and $b$ metre when the longitudinal tension is $5\, N$. The length of the string in metre when the longitudinal tension is $9\, N$ is

hard

A copper wire $(Y = 1 \times 10^{11}\, N/m^2)$ of length $6\, m$ and a steel wire $(Y = 2 \times 10^{11}\, N/m^2)$ of length $4\, m$ each of cross section $10^{-5}\, m^2$ are fastened end to end and stretched by a tension of $100\, N$. The elongation produced in the copper wire is ……… $mm$

medium

A steel wire can sustain $100\,kg$ weight without breaking. If the wire is cut into two equal parts, each part can sustain a weight of ……… $kg$

medium

(AIEEE-2012)

Which one is more elastic, steel or plastic ? Why ?

medium

A steel wire of length $4.7\; m$ and cross-sectional area $3.0 \times 10^{-5}\; m ^{2}$ stretches by the same amount as a copper wire of length $3.5\; m$ and cross-sectional area of $4.0 \times 10^{-5} \;m ^{2}$ under a given load. What is the ratio of the Young's modulus of steel to that of copper?

medium