Properties of Matter 1 Question 15
15. The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?
(1981, 2M)
(a) Length $=50 cm$, diameter $=0.5 mm$
(b) Length $=100 cm$, diameter $=1 mm$
(c) Length $=200 cm$, diameter $=2 mm$
(d) Length $=300 cm$, diameter $=3 mm$ Objective Question II (One or more correct option)
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Answer:
Correct Answer: 15. (a)
Solution:
- $\Delta l=\frac{F l}{A Y}=\frac{F l}{\left(\frac{\pi d^{2}}{4}\right) Y}$ or $(\Delta l) \propto \frac{l}{d^{2}}$
Now, $\frac{l}{d^{2}}$ is maximum in option (a).
