Physics Elasticity Question 138
Question: The extension of a wire by the application of load is 3 mm. The extension in a wire of the same material and length but half the radius by the same load is
[CMEET Bihar 1995]
Options:
A) 12 mm
B) 0.75 mm
C) 15 mm
D) 6 mm
Show Answer
Answer:
Correct Answer: A
Solution:
$ l=\frac{FL}{AY}\Rightarrow l\propto \frac{1}{r^{2}} $ (F,L and Y are constant) $ \frac{l _{2}}{l _{1}}={{\left( \frac{r _{1}}{r _{2}} \right)}^{2}}={{(2)}^{2}}\Rightarrow l _{2}=4l _{1}=4\times 3=12mm $
BETA
