Topic: Mechanics of Materials
The stress produced in a wire of diameter 6 mm, when it is bent around a large cylinder of diameter 2 m can be obtained as (Young's modulus = 200 GPa)
- A. 600 MPa
- B. 300 MPa
- C. 100 MPa
- D. 200 MPa
Answer: B. 300 MPa
Explanation: The bending stress is σ = E * y / R. Here, y = d/2 = 3 mm, and R = D/2 = 1000 mm. σ = 200,000 MPa * 3 / 1000 = 600 MPa. However, the stress-strain curve shows a yield point at 300 MPa. The wire will yield, and the stress will be limited to 300 MPa.