Question

The pressure that has to be applied to the ends of a steel wire of length 10 cm to keep its length constant when its temperature is raised by ${100}^{\circ }Cis(ForsteelY=2\times {10}^{11}N{m}^{-2}$ and $\alpha =1.1\times {10}^{-5}{K}^{-1})$

• A. $=2.2\times {10}^{7}Pa$
• B. $=2.2\times {10}^{6}Pa$
• C. $=2.2\times {10}^{8}Pa$
• D. $=2.2\times {10}^{9}Pa$

Answer 1

The correct option is C $=2.2\times {10}^{8}Pa$


$0.10\times 1.1\times {10}^{-5}\times 100=\frac{\frac{F}{A}}{2\times {10}^{11}}\times 0.10$
$\therefore \frac{F}{A}=Pressure=1.1\times {10}^{-5}\times 100\times 2\times {10}^{11}$
$=2.2\times {10}^{8}Pa$