JEE PYQ: Properties Of Matter Question 4
Question 4 - 2021 (24 Feb 2021 Shift 2)
A uniform metallic wire is elongated by 0.04 m when subjected to a linear force F. The elongation, if its length and diameter is doubled and subjected to the same force will be ____ cm.
Show Answer
Answer: 2
Solution
$Y = \frac{F/A}{\Delta\ell/\ell}$. For original: $\frac{F}{A} = Y \times \frac{0.04}{\ell}$ …(1)
When length and diameter doubled: $\frac{F}{4A} = Y \times \frac{\Delta\ell}{2\ell}$ …(2)
(1)/(2): $4 = \frac{0.04 \times 2}{\Delta\ell} \Rightarrow \Delta\ell = 0.02$ m $= 2$ cm
BETA
