Physics Elasticity Question 96
Question: Steel and copper wires of same length are stretched by the same weight one after the other. Young’s modulus of steel and copper are $ 2\times 10^{11},N/m^{2} $ and $ 1.2\times 10^{11},N/m^{2} $ . The ratio of increase in length
[MP PET 1984]
Options:
A) $ \frac{2}{5} $
B) $ \frac{3}{5} $
C) $ \frac{5}{4} $
D) $ \frac{5}{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ l=\frac{FL}{AY}\Rightarrow \frac{l _{S}}{l _{cu}}=\frac{Y _{cu}}{Y _{S}} $ (F,L and Y are constant)\ $ \frac{l _{s}}{l _{cu}}=\frac{1.2\times 10^{11}}{2\times 10^{11}}=\frac{3}{5} $
BETA
