JEE Main 2024 Physics question
Two metallic wires P and Q have same volume and are made up of same material. If their area of cross sections are in the ratio 4 : 1 and force F₁ is applied to P, an extension of Δℓ is produced. The force which is required to produce same extension in Q is F₂. The value of is .
Answer: 16
Solution
With the same volume, ℓ = V/A, so Δℓ = Fℓ/(YA) = FV/(YA²). The same extension gives F₁/A₁² = F₂/A₂², so F₁/F₂ = (A₁/A₂)² = 16.