Question

The length of a wire is l₁ when tension is T₁ and when tension is T₂. The natural length of the wire is

• A. $\frac{l_{1} + l_{2}}{2}$
• B. $\sqrt{l_{1}l_{2}}$
• C. $\frac{l_{1}T_{2} - l_{2}T_{1}}{T_{2} - T_{1}}$
• D. $\frac{l_{1}T_{2} + l_{2}T_{1}}{T_{2} + T_{1}}$

Answer 1

Answer: (C)

$\frac{l_{1}T_{2} - l_{2}T_{1}}{T_{2} - T_{1}}$

Answer 2

$\frac{T_{1}}{T_{2}} = \frac{l_{1} - l}{l_{2} - l}or$ T₁(l₂ – l) = T₂(l₁ - l) or

l = $\frac{l_{1}T_{2} - l_{2}T_{1}}{T_{2} - T_{1}}$