Two wires of the same material have lengths in the ratio 1 : 2 and their radii are in the ratio $1:\sqrt 2 $. If they are stretched by applying equal forces, the increase in their lengths will be in the ratio
A$2:\sqrt 2 $
B$\sqrt 2 :2$
C
1:1
D
1:2
Medium
Download our app for free and get started
C
1:1
c (c)$l = \frac{{FL}}{{\pi {r^2}Y}}$$ \Rightarrow l \propto \frac{L}{{{r^2}}}$ (F and Y are constant)
$\frac{{{l_1}}}{{{l_2}}} = \frac{{{L_1}}}{{{L_2}}}{\left( {\frac{{{r_2}}}{{{r_1}}}} \right)^2} = \frac{1}{2}{\left( {\sqrt 2 } \right)^2}$
$\frac{{{l_1}}}{{{l_2}}} = 1:1$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Increase in length of a wire is $1\, mm$ when suspended by a weight. If the same weight is suspended on a wire of double its length and double its radius, the increase in length will be ........ $mm$
The length of wire becomes $l_1$ and $l_2$ when $100\,N$ and $120\,N$ tensions are applied respectively. If $10l_2=11l_1$, the natural length of wire will be $\frac{1}{x} l_1$. Here the value of $x$ is ........
A force of $200\, N$ is applied at one end of a wire of length $2\, m$ and having area of cross-section ${10^{ - 2}}\,c{m^2}$. The other end of the wire is rigidly fixed. If coefficient of linear expansion of the wire $\alpha = 8 \times 10{^{-6}}°C^{-1}$ and Young's modulus $Y = 2.2 \times {10^{11}}\,N/{m^2}$ and its temperature is increased by $5°C$, then the increase in the tension of the wire will be ........ $N$
Two persons pull a wire towards themselves. Each person exerts a force of $200 \mathrm{~N}$ on the wire. Young's modulus of the material of wire is $1 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}$. Original length of the wire is $2 \mathrm{~m}$ and the area of cross section is $2 \mathrm{~cm}^2$. The wire will extend in length by . . . . . . . .$\mu \mathrm{m}$.
The maximum elongation of a steel wire of $1 \mathrm{~m}$ length if the elastic limit of steel and its Young's modulus, respectively, are $8 \times 10^8 \mathrm{~N} \mathrm{~m}^{-2}$ and $2 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}$, is:
A wire of length $L$ and radius $r$ is clamped rigidly at one end. When the other end of the wire is pulled by a force $f$, its length increases by $l$. Another wire of same material of length $2 L$ and radius $2 r$ is pulled by a force $2 f$. Then the increase in its length will be
Two wires $‘A’$ and $‘B’$ of the same material have radii in the ratio $2 : 1$ and lengths in the ratio $4 : 1$. The ratio of the normal forces required to produce the same change in the lengths of these two wires is
An aluminium rod with Young's modulus $Y =7.0$ $\times 10^{10} N / m ^2$ undergoes elastic strain of $0.04 \%$. The energy per unit volume stored in the rod in SI unit is:
Given : $\sigma$ is the compressibility of water, $\rho$ is the density of water and $K$ is the bulk modulus of water. What is the energy density of water at the bottom of a lake $‘h’$ metre deep ?