What must be the lengths of steel and copper rods at $0^o C$ for the difference in their lengths to be $10\,cm$ at any common temperature? $(\alpha_{steel}=1.2 \times {10^{-5}} \;^o C^{-1})$ and $(\alpha_{copper} = 1.8 \times 10^{-5} \;^o C^{-1})$
$30\, cm$ for steel and $20\,cm$ for copper
$20\,cm$ for steel and $30\,cm$ for copper
$40\,cm$ for steel and $30\,cm$ for copper
$30\,cm$ for steel and $40\,cm$ for copper
A horizontal steel railroad track has a length of $100 \,m$, when the temperature is $25^{\circ} C$. The track is constrained from expanding or bending. The stress on the track on a hot summer day, when the temperature is $40^{\circ} C$ is ............. $\times 10^7\,Pa$ (Note : The linear coefficient of thermal expansion for steel is $1.1 \times 10^{-5} /{ }^{\circ} C$ and the Young's modulus of steel is $2 \times 10^{11} \,Pa$ )
A steel wire is $1 \,m$ long and $1 \,mm ^2$ in area of cross-section. If it takes $200 \,N$ to stretch this wire by $1 \,mm$, how much force will be required to stretch a wire of the same material as well as diameter from its normal length of $10 \,m$ to a length of $1002 \,cm$ is ........ $N$
Two rods of different materials having coefficients of linear expansion ${\alpha _1},\,{\alpha _2}$ and Young's moduli ${Y_1}$ and ${Y_2}$ respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If ${\alpha _1}:{\alpha _2} = 2:3$, the thermal stresses developed in the two rods are equally provided ${Y_1}:{Y_2}$ is equal to
The following four wires are made of same material. Which one will have the largest elongation when subjected to the same tension ?
A metal rod of cross-sectional area $10^{-4} \,m ^{2}$ is hanging in a chamber kept at $20^{\circ} C$ with a weight attached to its free end. The coefficient of thermal expansion of the rod is $2.5 \times 10^{-6} \,K ^{-1}$ and its Young's modulus is $4 \times 10^{12} \,N / m ^{2}$. When the temperature of the chamber is lowered to $T$, then a weight of $5000 \,N$ needs to be attached to the rod, so that its length is unchanged. Then, $T$ is ............ $^{\circ} C$