The length of wire becomes l₁ and l₂ when 100 N and 120 N tensions are applied respectively. If 10 l₂ = 11 l₁, the natural length of wire will be 1 x l₁. Here the value of x is to be determined.
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Question

The length of wire becomes l₁ and l₂ when 100 N and 120 N tensions are applied respectively. If 10 l₂ = 11 l₁, the natural length of wire will be 1 x l₁. Here the value of x is to be determined.

Options

G1 Physics · Accepted Answer

Use stress σ=F/A, strain ε=ΔL/L and Young's modulus Y=σ/ε. For a uniform segment, ΔL=FL/(AY); for thermal restraint, thermal strain αΔT produces stress YαΔT. Evaluating the given data/statements gives A: 2. Therefore the correct answer is A.