WBJEE · Physics · Rotational Motion
A steel and a brass wire, each of length \(50 \mathrm{~cm}\) and cross-sectional area \(0.005 \mathrm{~cm}^{2}\) hang from a ceiling and are \(15 \mathrm{~cm}\) apart. Lower ends of the wires are attached to a light horizontal bar. A suitable downward load is applied to the bar so that each of the wires extends in length by \(0.1 \mathrm{~cm}\). At what distance from the steel wire the load must be applied? [Young's modulus of steel is \(2 \times 10^{12}\) dynes \(/ \mathrm{cm}^{2}\) and that of brass is \(1 \times 10^{12}\) dynes \(\left./ \mathrm{cm}^{2}\right]\)
- A \(7.5 \mathrm{~cm}\)
- B \(5 \mathrm{~cm}\)
- C \(10 \mathrm{~cm}\)
- D \(3 \mathrm{~cm}\)
Answer & Solution
Correct Answer
(B) \(5 \mathrm{~cm}\)
Step-by-step Solution
Detailed explanation
Hint: At equilibrium, Taking torque about point \(\mathrm{O}\)…
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