An aluminum rod (Young's modulus $ = 7 \times {10^9}\,N/{m^2})$ has a breaking strain of $0.2\%$. The minimum cross-sectional area of the rod in order to support a load of ${10^4}$Newton's is
$1 \times {10^{ - 2}}\,{m^2}$
$1.4 \times {10^{ - 3}}\,{m^2}$
$3.5 \times {10^{ - 3}}\,{m^2}$
$7.1 \times {10^{ - 4}}\,{m^2}$
A compressive force, $F$ is applied at the two ends of a long thin steel rod. It is heated, simultaneously, such that its temperature increases by $\Delta T$. The net change in its length is zero. Let $l$ be the length of the rod, $A$ its area of cross- section, $Y$ its Young's modulus, and $\alpha $ its coefficient of linear expansion. Then, $F$ is equal to
Which of the following statements is correct
The force constant of a wire does not depend on
Four identical rods are stretched by same force. Maximum extension is produced in
Two wires are made of the same material and have the same volume. The first wire has cross-sectional area $A$ and the second wire has cross-sectional area $3A$. If the length of the first wire is increased by $\Delta l$ on applying a force $F$, how much force is needed to stretch the second wire by the same amount?