Question

Two wires A and B are identical in shape and size are stretched by same magnitude of force. Then the extensions are found to be 0.2% and 0.3% respectively. Find the rate of their Young's modulii

• A. 2 : 3
• B. 3 : 2
• C. 4 : 9
• D. 9 : 4

Answer 1

The correct option is B 3 : 2

$\gamma A=\frac{stress}{strain}$

$stres{s}_A=stres{s}_B$

$\frac{{\gamma }_A}{{\gamma }_B}=\frac{{strain}_B}{{stress}_A}=\frac{0.3\times {10}^{-2}}{0.2\times {10}^{-2}}$

$=3:2$