Physics Elasticity Question 75
Question: The ratio of the lengths of two wires A and B of same material is 1 : 2 and the ratio of their diameter is 2 : 1. They are stretched by the same force, then the ratio of increase in length will be
[MP PMT 1986; MP PET/PMT 1988]
Options:
A) 2 : 1
B) 1 : 4
C) 1 : 8
D) 8 : 1
Show Answer
Answer:
Correct Answer: C
Solution:
$ l=\frac{FL}{AY}\Rightarrow l\propto \frac{L}{d^{2}} $
Therefore $ \frac{l _{1}}{l _{2}}=\frac{L _{1}}{L _{2}}\times {{\left( \frac{d _{2}}{d _{1}} \right)}^{2}} $
$ =\frac{1}{2}\times {{\left( \frac{1}{2} \right)}^{2}}=\frac{1}{8} $
BETA
