Verified Solution • 2025–26 Session
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QNEET-2018-Ph-916: NEET 2018 Physics - Class 11 NEET-2018-Ph-916 Solution: Two wires are made of the same material and have the same…
Two wires are made of the same material and have the same volume. The first wire has cross-sectional area A and the second wire has cross-sectional area 3A. If the length of the first wire is increased by on applying a force F how much force is needed to stretch the second wire by the same amount? 6F F 9F 4F
Multiple Choice Options
- A 6F
- B F
- C 9F
- D 4F
Step-by-Step Verified Solution
Let the wire 1 is of length = l and wire 2 of
length = l 3
Now area of wire 1 = A while area of wire 2 = 3A
For wire 1,
_ l = ( F A Y ) l ....(i)
For wire 2, let F' force is applied
_ l = ( F _ 3 A Y ) l 3 ....(2)
From equation (i) & (ii)
( F A Y ) l = ( F _ 3 A Y ) l 3
_ F' = 9F