Physics Elasticity Question 134
Question: A wire is stretched by 0.01 m by a certain force F. Another wire of same material whose diameter and length are double to the original wire is stretched by the same force. Then its elongation will be
[EAMCET (Engg.) 1995; CPMT 2001]
Options:
A) 0.005 m
B) 0.01 m
C) 0.02 m
D) 0.002 m
Show Answer
Answer:
Correct Answer: A
Solution:
$ l=\frac{FL}{\pi r^{2}Y} $ \ $ l\propto \frac{L}{r^{2}} $ (Y and F are constant) $ \frac{l _{2}}{l _{1}}=\frac{L _{2}}{L _{1}}\times {{\left( \frac{r _{1}}{r _{2}} \right)}^{2}}=(2)\times {{\left( \frac{1}{2} \right)}^{2}}=\frac{1}{2} $
Therefore $ l _{2}=\frac{l _{1}}{2}=\frac{0.01m}{2}=0.005m $
BETA
